[Nebthet]

I think I found the trick, at least for my tank, when using joe's juice or aiptasia x.

First you need to follow the instructions and drop a little in their mouth and cover the oral disk. Once that starts to disolve, shove the metal needle end into body of the aiptasia through where the oral disc was to the bottom and squirt the stuff all the way through it.

This is the only way I found, using these products that actually works to get rid of the whole anemone.