Zep Commercial 1-Gallon Scrub-Free Mildew Stain Remover is a powerful, no-scrubbing solution. Its industrial-strength formula quickly dissolves mold and mildew stains on toilet bowls, sinks, ceramic tile, grout, and other unpainted surfaces. Ideal for use both indoors and outdoors, this bleach-based product is effective on fiberglass, tile, and porcelain surfaces. Its ready-to-use formula eliminates the need for scrubbing, making it easy and convenient to use.