Baking soda and hydrogen peroxide: Combine two tablespoons of baking soda with one tablespoon of hydrogen peroxide to make a paste. Wet your toothbrush and dip it in the paste, then brush your teeth like normal. Do this once a week. 2. Coconut oil pulling: Swish a tablespoon of coconut oil around in your mouth for 20 minutes, then spit it out. Rinse with water and brush your teeth as usual. Do this every day. 3. Lemon juice and baking soda: Mix together equal parts of lemon juice and baking soda to form a paste, then brush your teeth with it. Rinse well afterward. Do this once or twice a week. 4. Apple cider vinegar: Rinse your mouth with diluted apple cider vinegar (mix one part vinegar with two parts water) once or twice a day. You can also use it as a mouthwash by gargling with it for 30 seconds, then spitting it out. 5. Eating certain foods: Eat plenty of crunchy fruits and vegetables like apples, celery, and carrots; they help remove plaque from teeth while you eat them. Also eat yogurt, which contains lactic acid that helps whiten teeth; cheeses, which also contain lactic acid; and nuts, which are abrasive and can help scrub away stains on teeth.