There's a good chance you have a brown bottle of hydrogen peroxide sitting in your medicine cabinet right now. Maybe it's been there for years. Most people reach for it when they have a cut, and then forget it exists. But that little bottle is doing so much less than it could. Hydrogen peroxide is one of the most versatile, science-backed natural disinfectants you can use in your home. At the right concentration and with the right technique, it kills bacteria, viruses, and fu