I have used FW exit, it does work. I ended up, pulling most of my live rock out and cooking it for a week, dipping all my corals and removing the plugs, then putting some on new plugs and what not's. I upgraded to a new tank, got a bunch more rock and transferred over. I also added several wrasses including a Sri Lanka Yellow wrasse, six line, and a Pinstriped Wrasse. If any made the trip over they didn't get established.
After my first attempt at FW-exit in my old system I still had a few in my system, I sucked them out with hose but never seemed to get them all, plus they seem to reproduce like crazy.