HHhhhhmmmm - wrasses - I had a Queen Coris Wrasse - BEAUTIFUL fish - BUT what did I know when I first started out! Until the bugger got big enough and started killing off my hermit crabs, and star-fish..... it actually re-arranged my aquascape for me, on a daily basis (lifting rocks up and moving them around)....
In the end, I unfortunately had to "break down" my tank to catch this bugger.... BUT, luckily for me, it was the same time that I upgraded to my 2 metre tank.... So, no, I did not use a "fish trap" - but I believe that it does work (I have caught many other fish using the "Coke bottle" trick (cut the top third off the plastic bottle, and place it back into the back end, inverted)....
Cheers. And Good luck!