One of the most popular do-it-yourself home teeth whitening methods is to use whitening strips and gels. They're easy to find, easy to use and top the market in sales. Gels are applied with a small brush, usually twice per day for about two weeks. Strips work the same way, but the gel is built in to small strips that are applied to the teeth overnight, generally for about the same length of time as the brush-on gels.
In both cases, peroxide works as the bleaching agent. Results can be seen in a few days and generally last for several months. While the strips and gels can be temporarily effective, they tend to address the front flat part of the tooth only, and not the grooves, nooks and crannies that reside in everyone's mouth. This is especially true with the strips, as brush-on gels are a bit easier to get full coverage. However, the gels rely on the product bonding to your teeth and remaining dry, which can be tricky to accomplish.