Peppermint shrimp - I bought one and he did not do a very good job at it, actually he did not survive...
I used Aiptasia-X with some success, just could not get everywhere. Bought another shrimp and this one does the job perfect, have had him a few months and no more aiptasia
A hypodermic needle and white vinegar does the trick to just got to be careful not to use to much it will drop your pH stab them with it inject no more aptasia or majanos
I've heard good things about bergia nudibranch's but never had the chance to use them.
Luckily, i can still pull the rock out and put a lighter under them for 30 seconds. They don't seem to survive being roasted real good.... you can almost hear their little screams