+1
I used this method over the weekend with a larger juice bottle and caught a yellow tang in under an hour. I modified the opening a bit to elongate the hole in order to accommodate the tall thin body of the tang.
I used that bottle trap and caught every fish in my tank but the damsel that I wanted out lol. In the end it was a quick ninja swipe of the net while the damsel was eating flakes off the water surface which led him to capture
That is one smart fish. LOL. That last trap you showed us is your best chance to catch it. You have to be patient. Don't worry. You will get him. If not, you can try feeding where the food floats on top of the water, wait until it gets close to the surface and quickly net him out like jackson6745 did.