arrow crabs don't only eat bristleworms--they also eat feather duster worms, etc, etc (I don't have my Calfo and Fenner Invert Book with me, so I can't give you more)
wrasse eat bristle worms, but don't depend on them to eat them entirely--try manual removal (with tweezers or tangle them w/ some baited filter floss)
try searching for bristleworm traps on google or yahoo--you will get a million designs and ideas