Rinse the stained area with cold water as soon as possible
Mix equal parts white vinegar and water
Soak the stain for 15 to 30 minutes
Gently rub the fabric together or with a soft brush
Apply liquid laundry detergent directly to the stain
Let it sit for 10 to 15 minutes
Wash the shirt in the hottest water safe for the fabric
Add oxygen bleach if the fabric allows it
Avoid using chlorine bleach on protein-based stains
Air-dry the shirt and check that the stain is gone before using heat
Repeat the treatment if the stain remains
For stubborn yellow stains, make a paste of baking soda and water
Apply the paste to the stain and let it sit before washing
Use an enzyme stain remover for old or set-in stains