You can make a worm trap by taking a 20cm piece of plastic pipe, blank off one end and drill a few holes in the pipe put some bait inside (prawn works well) and then block off the other end ,tie the trap to a small piece of live rock to keep it on the substrate.
For best results set the trap just before lights out and only leave it in there for about an hour, you will be quit amazed at how many worms you will catch.
Bristle worms are not bad for your tank there are however some bad guys just remove the bad ones
Good luck man