I found this post on "The Homestead Survival" website. According to them, using "Activated Charcoal" is the best way to whiten your teeth naturally. Would you try this? Click the link above to find out more.
How to use Activated Charcoal while brushing your teeth:
1. Place a small amount of toothpaste on the toothbrush and dip it in some Activated Charcoal.
2. Next just add just a little bit of water and begin to brush like normal.
3. Don’t be frightened by the black messy substance in your mouth, it will not stain your teeth or skin.
4. Rinse well… then rinse again.
5. Do warned that Activated Charcoal can stain clothing, so be careful.
6. This process will result in clean and bright teeth is beneficial for the body not toxic.