Bac-A-Zap Odor Eliminator - Quart (32_ounce) Active Live Bacteria and Enzymes This product is designed to be used indoors, as a grease build-up remover for drains, in wall voids, crawl spaces and garbage containers. To apply, dilute with water for maximum coverage. Use in wall voids, crawl spaces, basements, floors, walls, carpets at a rate of 3 fluid ounces per square yard. For bathroom and floor drains, simply apply 4 to 6 ounces daily for 5 days then use 4 to 6 ounces once or twice a week.