Hydrogen peroxide is a popular teeth whitening solution. It is sometimes used as a bleaching agent for hair. Before you use this chemical, do note that hydrogen peroxide can be dangerous if you do not practice safe dental practices.
For a start, ensure that the hydrogen peroxide is diluted with at least 1 part water to every 1 part peroxide. Be very careful not to swallow the solution. As a powerful reagent, this chemical can lead to blindness and even death if it is swallowed in large amount.
By the way, if you are wondering, it tastes pretty horrible but there are thousands of people who use it and have claimed good results from using it.