Some ppl inject them with: Kalk paste, boiling water, lemon juice, Joes juice(joe's right?), never heard of vinegar but Im sure it will work.
I bought a peppermint shrimp. He ate all mine.
Careful who you buy a peppermint shrimp from, I heard you can get some that arent true peppermints or something and they can cause some serious havock on a reef tank. And they are a pain to catch. No problems with mine, he hides in a cave, doesnt touch my corals, inverts or fish, and he eats aiptasia.
I found that the whole 'injection' thing got annoying after the first few times. Plus those anemones pull in and hide in a rock crevice when you get close. Little buggers.