try this.....
dun feed anything in the next few days
get those 1ltr coke bottles and chop off the top leaving a hole big enuf for the whitecheek to go in
then start feeding again but this time place food only in the bottle
wait for him get into the bottle....
when he does use ur hand to cover the opening,
when ur hand goes into the water, ur fish will confirm panic and try to swim str8 instead of swimming up the bottle
ur hands must be quick though
another method which i caught my bt, clam nipping pt, arc eye hawkfish and scopas
wait 4 hours afther lights out and make sure the fishes are sleeping in the tank...
then blast all the lights u have and stun all the fishes.
they will confirm swim out stunned and u can net them easily