one of my clams dies awhile ago too, and i thought it was bristle worms. it wasnt i never found out why it dies maybe a bristle worm was under it scratched it and it was an open wond then the worms would try and eat the infected area. i heard the traps work, i wouldnt know i just left mine alone. i had an arrow crab once that was a waste haha. i have heard if you put your clams up on rocks not in the sand the worms have less of a chance to be around it, but i wouldnt worry bout your worms like everyone said. they have just got a bad name, there not so bad at all.
60 ga. SPS tank w/ 2 - 175w 20k halides, korallin 1502 calcium reactor w/ph contorler
24ga. SW nano w/150 HQI
180ga. FW aggresive fish
125ga. FW w/60ga. sump. VERY aggresive fish