Thetford's RV Toilet Seal Lubricant & Conditioner is a perfect solution for prolonging the life of your toilet and holding tank seals. The product is formulated to penetrate the seal, conditioning and preventing it from deteriorating. You can use RV Toilet Seal Lubricant & Conditioner on RV and marine permanent toilets and on portable toilets. Toilet Seal Lubricant & Conditioner prevents waste from sticking, ensures smooth toilet operation, and is petroleum-free. How to use: Start of the season/ De-winterize. Pour 1/4 bottle into the toilet and let it stand for at least 8 hours before flushing. Longer contact time improves performance. During the season: Pour 1/4 bottle into the toilet and let it stand for at least 8 hours - longer contact time improves performance - then flush and use the toilet as normal. End of the season/ Winterizing: RV Toilet Seal Lubricant & Conditioner is compatible with RV/Marine antifreeze. Winterize the toilet leaving some antifreeze solution in the toilet, then add 1/4 bottle to the toilet and store for the winter.