good way to whiten teeth very fast?

whats a good way to do it at home to whiten my teeth that wont be harmful to me.
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What worked for me was the at home teeth whitening kits. I ordered some free trial offers on the net....2 kinds actually. Then after I got the results I wanted I bought some whitening toothpaste to maintain the whiteness. I didn't find that the paste alone worked....it is better for maintaining after a whitening.
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