Cleaning your teeth with baking soda once a week will aid in neutralizing the bacteria that cause bad breath. Using your stable tooth-brush, simply sprinkle a pinch of baking soda on the bristles, and then brush as normal. Baking soda can also be used as a mouthwash, just pour a half-teaspoon of baking soda into a small glass of water and let it dissolve, then fill your mouth with the liquid, without swallowing, and swish it around your gums and teeth.