If you mean shower silicone sealant that has turned black from mildew, the fastest fix depends on whether the mildew is only on the surface or has grown into the silicone.
Fastest method (for surface mildew)
- Dry the area completely
Wipe the shower silicone dry and let it air out. - Apply a strong mildew remover
- Spray a bathroom mildew cleaner, or use a solution of 1 part bleach to 10 parts water (avoid mixing bleach with vinegar or other cleaners).
- Soak paper towels or cotton strips in the solution and press them directly onto the silicone so it stays wet.
- Wait
- Leave it for 30–60 minutes (longer for stubborn spots).
- Scrub gently with an old toothbrush.
- Rinse and dry
- Rinse thoroughly and dry the silicone.
If the black stains remain
The mildew has likely penetrated the silicone. Cleaning usually won’t remove it completely. The quickest permanent fix is:
- Cut out the old silicone with a utility knife or silicone remover tool.
- Clean and disinfect the gap.
- Let it dry fully (ideally 24 hours).
- Apply new bathroom-grade, mold-resistant silicone sealant.
To prevent it returning
- Run the exhaust fan during and after showers.
- Wipe water from silicone seams.
- Keep shower corners dry when possible.
- Re-seal silicone when it starts cracking or discoloring.
For a rental or a quick cosmetic improvement, the bleach-and-paper-towel method is usually the fastest attempt; for deeply black silicone, replacement is usually the real solution.
