I got a pair supposedly a male and a female. After 6 months the "female" had grown faster than the formerly larger male and began to turn male and WWIII started. The male got the worst of it and stayed in the sand all day and was covered with visible cuts/ bite marks. Tried to trap the "female" literally caught every fish in the tank with the exception of two m. wrasses. Then one morning, the cowed male came out to eat and entered the trap. Bang! the formerly female entered and I had two fish locked in close quarter combat. Go them both out and put the wounded male in my QT tank. I gave him away after he healed.
The formerly female was put back into the display tank. Neither fish ever bothered anyone else. I have two large cleaner shrimp and they are left alone as is the a cleanup crew of snails and hermit crabs. I enjoy he, she or whatever but will not put two in a tank again.
As to trapping you wrasse, try a mirror with reflective side facing inward. If you use something like an aqua medic trap made out of clear plastic you might be able to use the wrasse's reflection as bait.
Good luck
RJA