Remove yellow armpit stains by rinsing the shirt after wearing it, soaking it in an enzymatic laundry detergent and washing at the hottest temperature safe for the garment. Add a cup of baking soda to the final rinse cycle to remove any remaining odor from perspiration.
- Rinse away the salts
Upon removing the shirt, rinse the arm pits under cool running water to dissolve the salts from perspiration. Hang the shirt to air dry if you do not plan to wash it immediately. This helps to eliminate stains even if you plan to send the shirt to a laundry.
- Soak the stain
Apply a small amount of enzyme-containing laundry detergent to each armpit. Work the detergent into the fabric, and allow the shirt to sit for 15 minutes before proceeding.
- Wash the shirt
Wash the shirt using the hottest temperature safe for the fabric and more of the enzymatic-laundry detergent. Add fabric-safe bleach to the wash cycle.
- Rinse with baking soda
Eliminate odors from sweat-stained shirts by adding a cup of baking soda to the rinse cycle.
- Check for complete stain removal before machine drying
The heat of a dryer sets many stains. Hang the shirt to air dry, and check for complete stain removal. If stains remain, repeat the soaking and washing procedure until they are gone.