2. Apple Cider Vinegar
Brushing with Apple Cider Vinegar is another proven teeth-whitening method, although those who administer it say that it takes about a month of regular brushing with the substance to notice a real difference. Specifically, this method shines in terms of removing the likes of coffee and nicotine stains from the teeth. One thing to note is that it is an acid, so following the administering of Apple Cider Vinegar, you should either brush thoroughly with a standard toothpaste or wash your mouth out well. If acid is left to dwell inside the mouth, it could end up eating away at the tooth enamel.