I agree with the ‘Just wash it!’ crowd. Unless you only wear disposable underwear and live in a sterile facility, you are already surviving this plague quite well whether you realize it or not.
Add a cup of white vinegar to the wash cycle and a second cup to the rinse cycle. Honest to Pete, vinegar is an excellent cleaning agent. When I was in the Army, vinegar is what we used to clean the sinks and toilets in the barracks. I still use it at home and my plumbing is the cleanest in the neighborhood. White vinegar not only cleans, it won’t bleach colors and it removes odors.
Edit: apparently sweatshirt can also mean hoodie, so my comment is mute.
Vinegar is good for cleaning sinks etc because, being acidic, it dissolves limescale. I can’t see that it would do much good for removing organic matter from clothes, though.
Wear it as is. When someone asks, “Hey, what’s that shit on your shirt” you can chuckle, knowingly.
It’s got to be either vinegar, lemon juice, baking soda or salt, hasn’t it? I mean, it’s always one of those things.
OK, if not that, try rubbing it with a cut potato, or wash it with pennies, or eggshells.
Or just wash it.
Isn’t “Shit on a sweatshirt!” a catchphrase on The Big Bang Theory?
If it had been a ShiteShirt, I don’t know what I’d have suggested.
Shades of Lisa Simpson gum-in-hair.