Post-brush. Helps prevent cavities. Shows proof of a cleaner mouth. Kills bad breath germs. Alcohol free. Listerine Smart Rinse is an anticavity mouthwash that helps protect teeth. It also cleans the mouth beyond brushing alone: Kills bad breath germs and cleans by removing food particles and bacteria, for fresh breath and a clean mouth feeling. Tints food particles and bacteria, leaving proof in the sink of a cleaner mouth.