How Do I Clean Black Mold in Shower Silicone? Fill spray bottle 2/3 full of white vinegar and add 2 tsp. of baking soda. Allow the fizzing to die down before installing the sprayer top. Spray the shower silicone and mold and allow the mixture to set for about an hour. This will kill the mold spores and keep them from continuing to grow and spread. Use an old toothbrush. Scrub all of the silicone and rinse it with very hot water.
Of all the from-scratch cleaners I've made, this is the best yet. It took up every last bit of mildew in the shower corners, which I had tried to eradicate with four different store-bought brands. I sprayed this concoction on (using the peroxide option), left it overnight, and it came right up with a washcloth and an old toothbrush in the morning.