I had my female matted filefish (Acreichthys tomentosus) in QT for 4 weeks where she was fed mysis, and some other frozen foods.
For the first few weeks after being placed into the DT, I didn't notice even a small dent in the aiptaisia population (I would say there were at least 50-75 anemones to start). I assumed that I had just gotten her used to eating frozen foods in QT, and I would have to try another method of aiptaisa removal.
Another 3-4 weeks went by, and I started to notice that the smaller aiptaisa anemones were dissappearing, followed by the medium, and eventually the largest had completely vanished. I never saw her eat a single one, but the only change that I had made to the system (and to my maintenance routine)during that time was adding the filefish.
After 6 months, my DT is now (at least visually) aiptasia free.
I was concerned that after the aiptaisa were gone, she might start ridding my tank of corals, but this turned out not to be the case. (I have a 120 gallon mixed reef with a few zoos and softies, but mostly LPS, SPS, and several Tridacnid clams).
Of course all fish are individuals, and I may have just lucked out with mine, but I wanted to share the success I have had with this fish. Hopefully you will start to notice a difference in your aiptasia population within the next frew weeks.
-Ben