I don't think a bloody shirt will be a problem, it depends how you paint it. I mean, people wear zombie shirts and skeleton shirts all the time but they are store purchased, (meaning, it looks professionally printed on) I've seen girls that have shirts that makes it look like they are a zombie wearing a corset,
i think it depends, I know i've seen these type of shirts a lot. the girls never get any problem, Im sure other kinds of zombie or gory shirts have been used, I think it might depend on how legit the shirt looks
and Some girl last year copied the outfit of the teacher from trick R treat with the huge blood stain on the side and she was let in.there were pics of it on fb.