Affresh Washer Cleaner removes and prevents odor-causing residue that can occur in all washers. While bleach only kills odor-causing bacteria leaving behind the detergent residue Affresh Washer Cleaner uses surfactant chemistry to remove the root problem. Affresh cleaner is a formulated slow-dissolve foaming tablet that gets under residue breaks it up and washes it away leaving the washer smelling fresh and clean. Simply place one tablet in the wash basket (without clothes) and run a Normal Cycle (hot option) or Clean Washer Cycle. Affresh brand is safe on septic tanks and safe for all washer components. Use once a month to keep your machine fresher and cleaner. Package includes six tablets.Please note that date on the package is production date and NOT EXPIRATION Date.