Here are some ways to get stains out of white t-shirts:
I'm a big fan of OxiClean! ...soak overnite
Try putting baking soda on the stain then pour on vinegar let fizz and sit.
I would use baking soda and peroxide, let soak overnight. Or you can use a cleaner degreaser, spray and let soak a few hours. You may have to use a soft toothbrush to get the entire stain out.
here is a couple solutions I found for you
Amway sells a cleaner that people swear by. They also guarantee their products. It is a spray clothes cleaner. Leather dye is tough to remove, so give this a try.
Make a slurry of hydrogen peroxide and baking soda. Spread it over the stain and gently rub it in. Launder as usual.
Mix a good amunt of oxiclean with a small amount of water and soak thestained area of the shirt in the mixture until the stain is removed, then launder and rinse well.
Hello Und21446745, get a microfiber cloth, add some put it on/around your scrubbing finger add hydrogen peroxide to it in the spot where your finger is and rub the stains, repeat until the stain is gone, then wash with other whites and a tiny (4 tablespoons) bit of bleach, if stain remains, repeat process, good luck, hope this helps you out.