Well here is something for you to use
compliments of yours truly.
Get a pvc
pipe with a cap for one end (or two). Either cap both sides or one side and saran wrap the other. Drill a small hole into the end of the cap in the center or whatever.
So you pretty much place some food inside the pvc
pipe and bury it up to the hole near the rocks or wherever the worms are. The theory is they will crawl into the hole that is on level ground with them and fall down and not be able to get out. Should help you out in getting rid of bristleworms.
i hate bristleworms