From some stuff I've read recently, listening to it might actually help. Apparently there's a theory that earworms are the result of your brain getting stuck on an incomplete memory (I've certainly had plenty of times where the worm is only part of the song), and by listening all the way through it can let go. (And not get more stuck, as our "common sense" interpretation would have it.)

Considering that a lot of mental processes are cause by focus on things to be completed, whether there's anything you can do about them at present or not, it makes a lot of sense.