3% Hydrogen Peroxide is the best thing to clear up ear infections, swimmers ear, kills bacteria, and over all cleaning out the ears, ect. I remember my grandma using it on me as a kid. It cleared up a lingering ear infection. Doc wanted to put tubes in. Never had another ear infection. I use on my girls and they never have had ear infections.
The armpit stain removal trick requires mixing just one part dishwashing liquid (it says Dawn, but you can probably use any brand) with two parts hydrogen peroxide, then let the mixture sit on the stain for an hour. For the worst kinds of stains, add baking soda and scrub. In no time no one would guess you were exercising in those clothes!