Fastest method for surface mold
- Ventilate the bathroom and wear gloves.
- Spray the affected silicone with a bathroom mold/mildew cleaner according to its label.
- Let it sit for the product’s recommended contact time.
- Scrub gently with an old toothbrush or small nylon brush.
- Rinse thoroughly and dry the area completely.
- Keep the shower well ventilated afterward to prevent it returning.
Important: Never mix bleach with vinegar, ammonia, acids, or other cleaning products. Use only one cleaning product at a time.
If the black mold is inside the silicone
If the silicone itself remains black after cleaning, the mold has likely penetrated the caulk. Cleaning won’t reliably remove it. The fastest permanent solution is to:
- Cut out the old silicone completely.
- Remove residue and clean the joint.
- Allow the area to dry thoroughly.
- Apply new bathroom-grade, mold-resistant 100% silicone.
This is usually much more effective than repeatedly bleaching badly stained silicone.
If you send me a photo of the shower silicone, I can tell you whether it looks like surface mold that can be cleaned or silicone that probably needs replacing.