There are many DIY tooth whitening methods, but this one will definitely sweep you off your feet. And, you won’t believe what the magic is all about. Aluminum foil. You first start by mixing baking soda, salt, and water to make a paste. Apply this paste on your teeth then apply a layer of tin foil on top of it. It should cover your teeth. Leave the foil on for one hour, then remove and brush your teeth as usual.