While the story is hilarious, I am wondering why you didn't throw the shirt out in the first place? I know that many people think everything should be recycled, but this is ridiculous.
I used to shop the charity stores for chore clothes about 20 years ago. People who shop charity stores want nice, neat, wearable clothing just like those who can afford to shop in regular stores. Not ratty, falling apart, ugly t-shirts that are ten years old. I believe it's not a donation if you [general] give something that you wouldn't wear yourself or is in poor condition. All you are doing then is having the charity take out your trash.
If you can't bring yourself to throw it out in it's entirety, cut the front off and use the rest for cleaning rags. Please don't "donate" it again.