Thursdays Tip of the Week - Mildew Mayhem - Grout is porous and absorbs oils from shampoos, conditioners, and soaps, which can lead to mildew growth that can spread to the tiles it surrounds. Clean mildew with a mix of 10 parts water to 1 part bleach and a soft-bristled brush. Follow up with a pH-neutral cleaner to remove the bleach solution.