Teeth whitening... do's and donts?

So i was lookin for a cheap effective way to whiten my teeth. ive heard hydrogen peroxide, baking soda, crest whitening strips. Are any of these bad for me to use? Whats the best road to take with these? And if they are not how often could i use them? Thanks
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you can swish with hydrogen peroxide, you just can't swallow it.I used to do that everyday and it worked well. My friend puts baking soda on her tooth paste and it works too. If you you either of the two there not bad for you unless you swallow them. I don't know much about the crest strips so i can't help you there.
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