As a kid my dad made me brush with baking soda and peroxide. We'd wet our brushes and dip them in a little cup full of baking soda and brush then we'd rinse and gargle with the peroxide and then water. I have very white teeth, especially considering how much coffee I drink. I'm not sure about the safety of it, it may not be a good idea to do it twice a day, maybe just in the morning is best then use a toothpaste with flouride in the evening.