For a rinse to make your mouth clean and stench-free, you need to feel the burn, right? Wrong. Alcohol, the ingredient in mouthwash that creates the discomfort, "reduces saliva production and causes dry mouth, which increases your risk of cavities," says Pia Lieb, a New York City-based cosmetic dentist. Instead of the booze-laced stuff like Scope, try a rinse like BreathRX or, for a cheaper option, Crest Pro-Health Rinse. They both contain something called cetylpyridinium chloride, which kills bacteria by messing with their cell membranes. [$10; breathrx.com; $5; crest.com]