Rinses are one of the newer at-home whitening products available over-the-counter. The concept is basically the same as whitening strips and gels, except that it comes packaged in a convenient mouthwash rinse. Some formulas are for whitening only, but you're more likely to find a "multi-action" kind of mouthwash that claims to whiten and strengthen teeth while helping to make your breath fresh. You use these mouthwashes just like you would an ordinary breath-freshening variety, except that you swish before you brush, not after. Peroxide is typically the whitening agent in rinses, and used twice daily should yield results in about 12 weeks. Because the whitening rinse is only in your mouth for a short period of time, most experts agree that it's the least effective way to whiten your teeth at home. At the very least, results take longer than with strips and gels.