I have one peppermint in my my display tank. There are no small aiptasia in that tank. But a few large ones he will not touch.
The Bherghias are fairly small nudi's. Not sure where mine went to, I think if you have crabs, they just might be dinner.
Copperbands do a wonderful job, the will also decimate any fans or tube worms.....just wish they would get the tube anemones. The copperband will just keep these trimmed, if you get rid of the fish, the aiptasia will grow back. I'm definately getting a copperband, as soon as someone can get my a Austrailian variety.