MS: DIY Underarm Stain Remover: 1 part Dawn (or any dishwashing liquid, I assume), 2 parts hydrogen peroxide, then add baking soda to create a paste. Use brush to work it in, and let it sit for 1 hour.
How to rid and prevent underarm stains. Crush 8 – 10 Aspirin pills in a small bowl. Add just enough water to make a paste. Work the paste into the stain. Let it sit on the stain overnight. Wash as you regularly do.
7 Tips to get rid of sweat stains from armpit, collar and cuffs
Goodbye to Yellow Armpit Stains: one part Dawn dishwashing liquid + two parts hydrogen peroxide + some baking soda. Use a small laundry brush to work the mixture into the stain for a few minutes. Let sit for an hour or so then launder as usual.
The armpit stain removal trick requires mixing just one part dishwashing liquid 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.