Good, I'll be interested to know which species they try. The majority of cones eat worms, and most eat polychaetes of some sort, but the ones I referred to, and several I didn't mention, eat the ones that aquarists usually call "fireworms," the ones with the bristles all along the side, and not just in tufts. I guess "bristleworm" is really a broad name for a lot of different species, but I think you were talking about the ones with the long bristles all along the margins. Not too many species will eat those. It will be interesting to hear the results!
Thanks,
Don