James (Photon) was experimenting with them awhile back. Not sure if he still has them or not, but the last I heard he wasn't too satisfied with the results he was getting. There's an extensive thread on this forum if you do a search for it. I've used a Klein's Butterfly and haven't seen any aiptasia since, although it does like to munch on leathers. Justin used a copperband butterfly, but I didn't have enought comfort about being able to get it to eat.