How To Get Rid of Yellow Armpit Stains--- 1 tsp dawn, tsp hydrogen peroxide, TB of baking soda. Mix together. Use small laundry brush and scrub it in. Let it stand for approx 1 hour and then launder as usual. ( instructions copied from this pin)
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.
One part Dawn dishwashing liquid mixed with two parts HYDROGEN PEROXIDE. Add baking soda for scrubbing help. Use laundry brush to work into the stain. Supposed to actually take yellow armpit stains out of white shirts!