I use Aiptasia-X in my 125 at home and it does a great job - I have a few pop up once in awhile. In my frag tank at work, for every one I nuked at least five new ones popped up the following week. I ended up euthanizing any frag with exposed skeleton and remounting the remaining frags before moving them to a new tank.Some folks say that, but I have great success with this type of treatment.
Sometimes they come back in the same spot after a few months, but never have I seen the treatment cause an outbreak.
It's firmly in the old wifes tale category for me. It just gets repeated over and over and over.