Bristle worms will only eat the dying or dead, in my first tank I had 3 clams with tons of bristle worms, they never went after a healthy clam.Correct me if im wrong but what's the issue with keeping a clam with bristle worms though they wouldnt eat a healthy clam i dont think would they? I have a few bristleworms I've seen not sure how many but never had a problem with my clams.
If you find them unsightly get an arrow crab, they love to munch on bristle worms.