I had that same problem and came up with the same idea. I put 3 peppermint shrimp in a 30 gal fuge and they wiped out my aiptasia in about a week of so, but after that I noticed a big decrease in the number of critters. I gave 2 of the shrimp to a firend of mine and put 1 in my quarintine tank (just in case I see aiptasia coming back) and now the critter population is coming back. So my experience is that they can be used temporarily to rid aipstasia but when they're done take them out or they'll eat everything.