Hydrogen peroxide is not suitable for cleaning bedsores as it can cause more damage, according to MedlinePlus. Instead, use mild soap and water to clean a stage I bedsore, or salt water or a doctor-approved cleanser for a stage II sore.
Consult with a doctor for advice on how to clean a stage III or IV bedsore. A stage I bedsore is a red, sore area on the skin that indicates the formation of a pressure sore. A stage II sore is when the skin blisters and creates an open sore. Stage III bedsores have a sunken hole in the sore, called a crater. Body fat might be visible at this stage. In a stage IV bedsore, the sore is deep enough to damage muscle tissue and bone.