Someone in our local club used the Vossen larval trap and only caught 6 fry along with loads of mysids.
My clowns refuse to lay on a tile, and will knock over anything that I try to use to cover their favorite rock. So on hatch night I turn off all the light, pumps, and powerheads. After about 45 mins I check the tank and usually find the majority of the larvae have hatched. I then shine a penlight at the corner of the tank and skim them off the surface with a shallow bowl when they approach the light. A little labor intensive but I lose very few larvae this way, and my clowns don't really give me any other options.