I've managed to spot treat out aiptasia from tanks, but typically only when I find it on the frag, then check regularly until I find the other two or three I didn't know were there. You have to be *very* diligent and very lucky. If you have one in your overflow box, sump, etc., it will keep spreading.
Take the rock out and dry it out is the best bet.
Next best is to burn the bugger out (I've used a nail heated on the stove, held with pliers), then cut out the section of rock (I'll scrape as well, but never in the tank), then rinse the whole thing, then cover it in a thick kalk paste (or the item of your choice), then return it to the tank and make sure the kalk paste is still there. For some reason if I let it sit a few minutes I don't have an issue with it blowing around the tank and causing a pH spike.
Seeing as we're talking about heat and live rock out of tanks I'm going to remind you that palytoxin is real.
Berghia were wildly successful for me once, and utterly useless the other. Depends if they are successful breeding in your tank IMO.