Formula Tuning
Tune the formula and scent for dirt or mildew
Bathroom Mildew & Grout Cleaning Solution
The right grout cleaner depends on whether black grout is dirty or moldy. If the color lightens when you scrub, it's soap scum, grease, and body oil sitting on the surface, and an alkaline oxygen grout cleaner brightens it. If black spots have grown into the grout, shower caulk, or window seals and won't scrub off, it's mildew, and it needs a chlorine stain remover left to dwell until the color fades. CleenU matches two ready-to-use cleaners to the stain and makes private-label and OEM/ODM grout and mildew cleaners for brands, distributors, and online sellers.
Free Samples
Samples are usually ready in 3–5 days
Custom Packaging
Trigger, bottle size, grout brush kits, and label language
OEM/ODM
Private-label grout and mildew cleaners from 500 bottles
Black Grout: Dirt or Mildew?
For dark soap scum and grease on the surface of grout lines, spray an alkaline oxygen grout cleaner along the lines, wait 5–10 minutes, scrub back and forth with a grout brush, and rinse. For black mildew that won't scrub off, and for mildew on shower caulk, window seals, and wall corners, open a window, run the fan, spray a chlorine mildew stain remover, wait 10–15 minutes (30 for stubborn stains), and rinse once the color fades. Never mix the chlorine remover with acidic or ammonia cleaners, and spot-test colored grout first.
- Why It's Black: Surface dirt that scrubs off and mildew that won't each call for a different product.
- How It Works: An alkaline oxygen formula breaks down soap scum and grease and brightens grout; a chlorine formula fades mildew.
- How to Use: Ready to use. Grout dirt sits 5–10 minutes, then scrub; mildew sits 10–30 minutes, then rinse.
- Surfaces: Fine on cement grout, tile, and silicone; spot-test colored grout and caulk, and keep off fabric.
- Ventilation & Safety: Open a window, run the fan, wear gloves, and never mix chlorine with acid or ammonia.
- Cleaning Areas
- Grout lines, shower caulk, window seals, and wall corners
- Surfaces
- Cement grout, tile, and silicone
- Formats
- Oxygen grout spray, chlorine mildew stain spray
- Service
- OEM/ODM from 500 bottles
Where to Use It
Grout Lines
Dark soap scum and grease on the surface: spray the Grout Cleaner along the lines, wait 5–10 minutes, scrub with a grout brush, and rinse.
Shower Caulk
Black mildew on silicone: ventilate, spray the Mold & Mildew Stain Remover, wait 10–15 minutes, and rinse once faded.
Window Seals
Mildew on window frame and sill seals: spray the remover, let it dwell, and wipe with a damp cloth, keeping curtains clear.
Wall Corners
Mildew in tiled corners: fade it with the Mold & Mildew Stain Remover; spot-test painted walls first.
Spot-test natural stone, coated, and wood surfaces in a hidden area first.
When Not to Use It
- Acidic cleaners and ammonia products: the chlorine mildew remover releases harmful gas when mixed with them, so rinse with water before and after.
- Colored grout, epoxy grout, and colored caulk: chlorine products can lighten the color, so spot-test in a hidden area first.
- Towels, shower curtains, and clothing: chlorine overspray bleaches fabric, so move them out first.
- Caulk and grout that's cracked, crumbling, or peeling: cleaners only fade stains and can't repair them, so re-caulk or regrout damaged areas.
Choose by Stain Type and Location
Soap Scum and Grease on Grout Lines
Grout Cleaner- Surface
- Cement grout lines in bathrooms, kitchens, and balconies
- Note
- Spot-test colored grout; use the mildew remover for mildew grown into grout; never mix with chlorine or acidic products
- Use Method
- Spray along the lines, wait 5–10 minutes, scrub with a grout brush, and rinse or wipe
- Customization
- Scent, trigger, bottle size, and grout brush kits
Alkaline oxygenBrightens groutFresh soap scent
Mildew on Shower Caulk and Window Seals
Mold & Mildew Stain Remover- Surface
- Shower caulk, window seals, grout lines, and tile walls
- Note
- Never mix with acidic or ammonia cleaners; can bleach fabric and colored grout
- Use Method
- Ventilate, spray, wait 10–15 minutes (30 for stubborn stains), and rinse once faded
- Customization
- Trigger, bottle size, and chlorine warning labels
Chlorine formulaDwell to fadeUnscented
Mildew on Tile Walls and Corners
Mold & Mildew Stain Remover- Surface
- Bathroom tile walls, corners, and tiled ceiling edges
- Note
- Spot-test painted walls; keep off fabric and metal fixtures
- Use Method
- Run the fan, spray, wait 10–15 minutes, wipe clean, and keep the room dry
- Customization
- Trigger, bottle size, and chlorine warning labels
Chlorine formulaUse with ventilationRinse after fading
Recommended Products
Grout Cleaner
- Surface
- Cement grout lines in bathrooms, kitchens, and balconies
- Strength
- Alkaline, pH 9.5–11.0
- Foam / Trigger
- Clear gel, applied along grout lines with the nozzle; used with a grout brush
- Packaging
- 200 mL precision-nozzle squeeze bottle; other bottles customizable
Mold & Mildew Stain Remover
- Surface
- Tile walls, grout lines, shower caulk, and window seals
- Strength
- Alkaline chlorine, pH 11.5–13.0
- Foam / Trigger
- Spray
- Packaging
- 500 mL trigger spray; 1 L refill available
Not sure which one to choose?
Tell us what you are cleaning, the surface, and how you clean it, and we will point you to the right product or formula.
Get Product AdviceWhy Choose CleenU
Formula Development
We tune the formula, scent, and effect on colored grout separately for surface dirt and mildew.
Sample Testing
Free samples are usually ready in 3–5 days, then tuned for brightening, fade speed, and scent based on your feedback.
Customization
Trigger, bottle size, chlorine warning statements, label language, and grout brush e-commerce kits.
Consistent Supply
Each formula keeps batch retention samples and a COA, so color, scent, and feel stay consistent on reorders.
How an OEM/ODM Project Works
- 01Share Your Brief
- 02Formula Recommendation
- 03Free Samples
- 04Packaging Approval
- 05Production
- 06Shipping
OrderingDetails
- MOQ
- 500 bottles for standard projects
- Sample Lead Time
- Free samples, usually ready in 3–5 days
- Production Lead Time
- Scheduled with the order after packaging and labels are approved
- Documents
- SDS/MSDS, TDS, and batch COA, sent on request
Compare the Options
Three common grout and mildew jobs, compared by product, pH, foam, and method. Surface dirt comes out with an alkaline oxygen formula and a grout brush; mildew grown into grout, caulk, and walls fades with a chlorine formula left to dwell. The two have opposite chemistry and must never be used together.
| Cleaning Job | Where | Strength | Foam | Method |
|---|---|---|---|---|
| Dark Grout Lines | Grout lines | Alkaline, pH 9.5–11.0 | Low | Wait 5–10 minutes, then scrub with a grout brush |
| Caulk & Window Seals | Shower caulk and window seals | Alkaline chlorine, pH 11.5–13.0 | Low | Wait 10–15 minutes, rinse once faded |
| Wall Corners | Tile walls and corners | Alkaline chlorine, pH 11.5–13.0 | Low | Ventilate, wait 10–15 minutes, wipe, and keep dry |
How to Use It
- Scrub First
Scrub a spot: if it lightens, it's dirt; black spots that stay are mildew.
- Test and Ventilate
Spot-test colored grout and caulk, open a window, run the fan, and move fabric away.
- Clean as Directed
Keep to the label's dwell time, never use both products at once, and never mix with other cleaners.
- Rinse and Keep Dry
Rinse thoroughly, wipe up standing water, and keep the room ventilated to slow regrowth.
FAQ
Frequently Asked Questions
Common questions about how to use it, which surfaces are safe, and private-label orders.
Use & Cleaning
How do you clean black grout?
Scrub a spot with a grout brush first. If it lightens, it's soap scum and grease: spray the grout cleaner along the lines, wait 5–10 minutes, scrub, and rinse. If black spots stay, it's mildew: ventilate, spray the mold and mildew stain remover, wait 10–15 minutes until the color fades, and rinse.
How do you remove mold from shower caulk?
Open a window and run the fan, spray the mold and mildew stain remover on the moldy caulk, wait 10–15 minutes (30 for stubborn stains), and rinse once it fades. If the caulk is cracked or peeling, cleaning only fades it; cut it out and re-caulk.
How do you get rid of mildew on bathroom walls?
On tiled walls and corners, spray the mildew stain remover, wait 10–15 minutes until the color fades, wipe with a damp cloth, and keep the room ventilated and dry. Don't spray chlorine directly on painted drywall without spot-testing, since it can bleach the paint.
Surfaces & Safety
Can I use the grout cleaner and mildew remover together?
Not at the same time. The two have different chemistry, and the chlorine remover especially must never meet acidic or ammonia products. Use one, rinse thoroughly with water, then use the other.
Can I use these on colored grout?
Spot-test first. The chlorine mildew remover can lighten colored grout and caulk; the grout cleaner is gentler, but colored lines should still be tested.
Why does mildew keep coming back?
Mildew thrives in damp, poorly ventilated rooms. After cleaning, run the fan, wipe up standing water, and keep the bathroom dry. These are stain cleaners and make no disinfecting or antimicrobial claims.
Private Label & Sourcing
What should I prepare before asking about a private-label grout cleaner?
Settle four things: surface dirt or mildew focus; whether to bundle a grout brush; scent and bottle size; and your market's labeling requirements for chlorine products. Then we'll arrange free samples, usually ready in 3–5 days.
What documents come with an OEM mildew stain remover?
We provide SDS/MSDS, TDS, and batch COA, and prepare chlorine warning statements and label copy for your target market. These documents aren't posted for download; we send them on request after you inquire.
What are the MOQ and lead time for grout and mildew cleaners?
Standard projects start at 500 bottles. Free samples are usually ready in 3–5 days, and production is scheduled after packaging and labels are approved.
Keep Exploring
Related Guides
Launching a Grout or Mildew Cleaner? Start with Free Samples
Black grout comes down to dirt versus mildew: scrub surface soap scum and grease out with an alkaline oxygen grout cleaner and a grout brush, and fade mildew in grout, caulk, and window seals with a chlorine stain remover left to dwell. Never mix the two, and keep the room ventilated and dry. If you're launching your own grout or mildew cleaner, CleenU can start from these two formulas, with free samples first and a 500-bottle MOQ.
Tell us your target market, what you clean, and your packaging ideas. Free samples are usually ready in 3–5 days.