<human>:  What's the best way to whiten my teeth at home without harmful chemicals?
<bot>: The best way to whiten teeth at home without harmful chemicals is to brush with a mixture of baking soda and hydrogen peroxide. Baking soda is a natural cleanser that can help remove surface stains and hydrogen peroxide is a mild bleaching agent. Additionally, you can also try oil pulling with coconut oil or using a straw when drinking coffee or tea.