303 30574 Mold & Mildew Cleaner + Blocker. 303 Mold & Mildew Cleaner + Blocker quickly and safely cleans and removes tough mold and mildew stains from virtually any water-safe surface. Unlike other mold & mildew cleaner products on the market, this product does NOT contain bleach, and will leave behind a fresh scent, with no strong odors to worry about during or after use.
