Easy, coat yourself in schisse and piss, stick some poisonous frogs and the like in there, and listo. Although I prefer Koel's approach of climbing up the throat his way back out with knifes.
Alternatively, you could take the fun approach and attempt to knit a sweater using the eater's instestines. Bonus points if you do so without removing said intestines from the body.
I don't think such mundane approaches would work on a Cardinal Sin. If Glenn has time before he finds out he is a target, perhaps he could do some research (he's just made a very knowledgably ally with a vast library) into what Gluttony doesn't like, or avoids consuming.
I don't know. I imagine that dealing enough physical damage would work on anyone with a body. Granted, getting to that point is the real problem here, but I still think it's a viable tactic.
Very true. Unless you count both of us pretty much passing out before we even hit the foreplay, even though it was mutually decided upon to fool around *laughs*