Problems catching a fish?

Day 5 of trying to catch a royal gramma and still nothing.

Has anyone have any suggestions when it comes to catching a right pain of a fish?

I've tried the bottle technique pleanty of times, this is the first time it has not worked. I've tried using a bag with bait, the bottle with bait, catching at night with all the lights out, trying to get him into a rock and removing it. everything.

Tank is 100gallon SPS reef.

Some of my other fish are starting to look very sickly, all I'm doing at this point is stressing the fish out.

I havn't fed the tank in 5 days which may be another reason for the blenny and firefish not looking the best. The regal is sick because I'm moving traps in and out, and the gramma keeps going for him.

The gramma is seriously not looking well, he just floats there on his side gasping, yet all attempts in catching him just are not working and all it's doing is stressing him out more. All other fish are out and about bar the gramma.

I really do not want to dismantle the tank, all it would do is stress out the regal tang more, possibly to death, and I honestly don't want to do that.

So has anyone have any idea to get this bloody fish out my tank?

My uncle did suggets a piece of food tied to a string, anyone else tried this? would it work?