How can I whiten my teeth naturally?

I heard that bleaching them strips a layer of enamel so how can I do it naturally?
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brush your teeth with arm and hammer baking soda, not the tooth paste with it in it, but the real stuff. i know its going to taste disgusting but it works. just do it once a day or once every 2 days but continue to do it until you notice a difference and are happy with the whiteness of your teeth
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