How do you use Baking soda to whiten your teeth?

I need directions and stuff.
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Ok. This is what I do. I wet my toothbrush, and put a pea sized amount of toothpaste on it. Then, I get a metal spoon, and scoop some baking soda out of the box, and rub the toothbrush on the spoon, which in turn picks up the baking soda onto the brush and toothpaste. Then, I brush as I would regularly do. Hope this helps :)
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