Salifert Flatworm Exit (or levamisole) will not kill AEFW unless you use such a high dose that the corals will suffer too.
KZ Flatworm Stop at a double dose will interrupt their life cycle and not allow them to reproduce anymore. It will not kill the worms, but it does make them die childless, so you are flatworm free in 3-5 months when the big ones die of old age. This works great for an in-tank treatment, but it takes time and the product is not super cheap for larger systems. Some fools use it and don't know how to read and post that it did not kill the worms, but nobody ever said that it would.
UWC has a product called Purge that has a VERY wide range of results from successes to complete tank crashes. The most typical result is that some worms die, but not all. I would stay away from this.
Bayer will kill AEFW. Guaranteed. I sometimes mix a dip of up to 15-20% Bayer since it is safe on all acropora that I have ever seen. CoralRx and Revive will too. So does melafix.
The Flatworm Stop can be good if you have time since it will save the stress of daily dips. Eventually these can take a toll on some corals. If you are going to dip, make sure that you dip all of the stuff in the tank and even clean it out and wipe it dry. They nasty buggers can hide out on the glass, seams and pumps sometimes.
There are some natural predators that will eat stuff, but they cannot get inside of colonies where the infestations occur.