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!
Use Vinegar and Baking Soda to Recharge Your Towels
10 Laundry Boosters Using Vinegar! Color Brightener Color Protector Whiter Whites Restore Whites Preserve Linens Yellowed Items Reviver Heavy Duty Pre-Soak Lint Busters Fabric Softener Ring Around The Collar Remover