S.M.
I have a friend with beautiful white teeth, and she is a huge coffee drinker, so I asked her one day how her teeth were so white and she swore that she rinsed with straight Hydrogen peroxide every day... I tried it ad it taste terrible so I mix it with a little Listerine whitening formula just to give it minty flavor, and it worked great... with in three days I noticed a big difference, but WARNING DO NOT SWALLOW IT! that would not be good for you, but it worked great, I'd rince for a minute then brush.