The problem with using sunfish is that they will only be able to eat small crayfish, so depending on what sizes are in there, you may want to use something else. Why not just net them? Or use a trap? There cant be that many in there....
Your right a full grown large sunfish (Redbreast, Green, Pumpkinseed, Warmouth,Redear) wont eat Crayfish over 5 inches right off the bat......theyll wait until they molt! Recipe sounds good, we just used to fry'em in Butter (Ozark Mountain Lobsters).