Joes Juice, or just injecting them with real lemon juice works, or doseing them wirth kalkwasser also works. True peppermint shrimp are an iffy proposition as some may eat them others may not.
Another tired and provenmethod is tosmother them out. Use a piece of styrofoam coffee cup, just a tiny smidgen of 9t, and push it in the hole the aipstasia retreats into in the rock. The styrofoam seals it in place and prevent s it from coming back out and it kills it..yu do not notice the foam piece and in no time it discolors and you forget where its even at.If it ever does come out of the hole the foam is not going to hurt anything and the aip is long been dead.