I have a couple of 'helpful friends' in the form of cleaner shrimps that interfere whenever I put my hands in the tank. Even have to feed them a morsel to keep them happy while trying to grab the bristleworm - so trying to leave 'exposed' bait doesn't work. They were my whitespot secret weapon
I even tried a cannister with holes in it with scallop/whitebait inside but to no avail. Not even nibbled.
Probably take up Steve's worm trap offer, then try banded shrimp, then try shotgun...
Its bad enough having some nice leathers chomped but I also have a few things in tank like anemones and elegance corals which don't need bristleworms eating their toes!