Whiten natural nails:  Lightly file the top of your nails to get the stains off.  Put about 1/2 cup of HOT water in a bowl.  Add 4 tablespoons of baking soda and stir until mostly dissolved.  Add 2 tablespoons of peroxide.  Soak nails in the solution for about a minute  (You can soak them longer if you have the patience, I don&#39;t! It works quickly though.)