Does this happen to your shirts?
Get a biologically safe, plant based stain remover like ECOVER from Whole Foods.
Take some water...
... and apply it to the shirt.
Squeeze out a tiny bit of the stuff.
Use the bottles brush to rub the stain with moderate force a couple times..
You will immediately see most of the stain come out.
Now do the same to the sleeves.
Add your favorite environmentally friendly detergent.
Throw in the shirt with everything else.
Set it to cold cycle or whatever you like...
Read a book.
See? Nice and kleen.
Then into the dryer.
Now you're lookin' good!