Ouch. That's rough, Glorb. That's worse than the song I had stuck in my head last weekend which was the little cooking song Chiyo-chan sings in the first episode of Azumanga Daioh. It's not a bad song, it's quite cute actually, but it's only about five seconds long.
Ironically, I find that the best way to get a song out of my head is to actually listen to it. But in your case...I dunno...