Scrape off any excess mustard with a dull knife or spoon
Rinse the stain from the back with cold water
Apply liquid laundry detergent or dish soap directly to the stain
Gently rub the fabric together or use a soft brush
Let it sit for 5 to 10 minutes
Rinse thoroughly with cold water
Repeat if the stain remains
If needed, soak the item in cold water with laundry detergent for 15 to 30 minutes
Wash the clothing according to the care label
Check that the stain is gone before drying
Air-dry the item if any stain remains
Treat stubborn stains with a stain remover or a paste of baking soda and water
For white or colorfast fabrics, use diluted hydrogen peroxide only if safe for the fabric
Avoid hot water and machine drying until the stain is fully removed