Joe's Juice does work but you have to realize that you can have one little piece growing somewhere in your tank that will eventually turn into an Aiptasia. I have found in my own system that I have been unsuccessful in completely eliminating the little buggers. I have recently found some larger ones that were hidden back in-between rock groupings.. I'm hoping these were the major spawners and have at least gotten them out of the tank. It really is amazing where they can spawn and what nooks and crannies they can get into and survive.
hth.
hth.