Can you use ordinary bleach to whiten your teeth?

No don't do it-it is very dangerous. Bleach is 6 percent acid and poisonous. Try Baking Soda- you will be surprised. I discovered this by accident after spending a fortune on special toothpastes. Just put a little on a wet brush and brush (gently) all your smile teeth, but only when needed.It is in many toothpastes so completely safe but try not to swallow, it is very bitter.