I've had some luck with a handful of dried dogfood, as long as it's large enough not to go thru the mesh. I usually end up with shiners, minnows, and sometimes some crawdads as a bonus, on top of the perch.
tear up a couple of white styrofoam cups and throw it in the trap...this will draw in perch. You can also cut an onion in quarters and throw it in there, works even better. Range Cubes/dog food in a small burlap sack or in panty hose also works well...the burlap sack/hose keeps it from dissolving too quickly, but lets the flavor get out in the water.