We had a relatively new employee once drudging sand in the invert system to pull all the snails/hermits up to a pedestal so we could filter out the empty shells (which we do periodically). Live critters will move from the pedestal eventually leaving behind only empty shells.
Well...he forgot to put on gloves before doing so. That tank had a LOT of bristle worms in it. Vinegar does work wonders. I'm surprised it hasn't been confirmed in this thread yet, but yes...it does work. The vinegar dissolves the spines. We keep a vinegar mix in a spray bottle for cleaning. All it took was a few sprays to his hand and it stopped relatively quickly. You don't want to break the spines off in your hand. As one other mentioned here...they can be quite annoying under the skin for an extended period of time.