+1 on McLube for the sail track.
Had a pro rigger tell me never to use WD40 on anything. He said there is something better for whatever you're using it on (engine or rigging) and he gave me a can of T9. That seems pretty good for unlocking stuck nuts/bolts and stays on as a lubricant as well. Just his opinion, I haven't done much else research.
1985 Catalina 30 Std Rig "A Cenoura"