This sounds so easy and cheap.... am I missing something?

"The best cure for dog mange is to mix a 1% hydrogen peroxide solution with water and add borax. Dissolve thoroughly. Wash the dog with it once a week. Do NOT WASH THE solution left on the dog with ANY WATER. Do not wipe the dog dry. The solution will take effect on mange. The treatment period should not be longer than a month or two. The dog will probably not be resistant as the treatment is painless. This has worked well for me."