My mom told me that you can dip your wet tooth brush into a bottle of peroxide, then brush your teeth with it. Over time, your teeth will become much whiter. Just don't swallow the peroxide. I have found that it works after about a week of daily use. The bottle of peroxide only costs .99 at most drug and food stores.
By McCollonough from TN
This page contains the following solutions.
My dentist said never use the hydrogen peroxide full-strength in your mouth. Said full-strength it is damaging to tissue. He said to dilute Hydrogen Peroxide to one part Hydrogen Peroxide and 2 parts water.
Salt has natural preservatives for marinating foods. It is also good for removing stains and grease. The salt also can be a teeth whitening and can prevent of bad breath.
When using Crest Whitestrips (and using their $7.00 coupon, of course), don't throw away the little whitening part that doesn't peel off.
Although the price of professional teeth whitening has come down, it can still be outside of your budget. This is a page about frugal teeth whitening.