you have a few options,
copperbanded butterfly's are hit or miss kinda like pepermint shrimp..but they are also known as a somewhat difficult fish to keep happy. I havent tried this method yet but many others have done it with success though they sometimes turn to eating zoanthids as well
Berghia nudi's is another natural option. been breeding these lately and some that got them from me have had great success (with patience) and i have yet to put any in my tank though ill probalby be doing that soon. they go online for too much money 15 plus shipping each and dependin on teh size of the tank and how spread out the aiptasia are, what fish...they are no gauruntee but the ones i have in my breeder set up eat anywhere from 1-6 aiptasia a day non stop.
ive heard really good things about zap-tasia which is like kalk/joe's/aiptasia-x but have not first hand experience again...ive seen it in a friends tank its its more like coating them with superglue gel so it stays with them much better...i know roozen (dc area) sells it and a few others online..i think glass box designs did a write up on it as well
Manual removal is the last effore. just need to make sure you get every bit of the aiptasia off the rock or it will grow back.
ive heard other boil rocks but that would just staank.
good luck. i know the feeling of frustration it brings, my tank is basically a ton of sps, zoanthids, and majority aiptasia.