Get rid of grease stains on shirts - and yellow 'pits! Grease: 1 tsp. Dawn dishwashing detergent, 3-4 tablespoons of hydrogen peroxide, and a couple tablespoons of baking soda. Yellowing: one part Dawn dishwashing liquid mixed with two parts hydrogen peroxide and some baking soda.
TESTED: How to Actually Remove Yellow Sweat Pit Stains