There are a couple of traps you can try, but I probably wouldn't. Bristleworms are fantastic detrivores, and like FW snails, their population is kept in check by the amount of food available. I personally like them in my tank--an easy thing to monitor, and otherwise pretty safe. Large ones can go after fish and clams, but these are usually easy to spot and remove--and I've only heard one case of them getting a healthy fish.
Most bristleworms are not hazardous to humans. The skin on our fingers is to thick for their spines to penetrate, and most have little to no toxin. Larger specimens (more than 6 inches long) can be a threat to the unwary, and there are species, collectively called fire worms, that do have a toxin in their spines. These look fuzzier, and the spines tend to be whitish, as opposed to the black and red of the common ones.
For traps--cut off the top of a 2 liter bottle. Invert it in the sand and bait it with a chunk of food. Be prepared to release lots of crabs and such, as they will also be caught.