Has anyone tried the Mr Clean Magic Eraser? It cleans almost anything and has no odor and almost zero residue (which a quick wipe with a dry rag should take up.) I haven't used in on track but with my hottub it did wonders removing the iron scale from the water level. I used to scrub and scrub with a sponge scouring pad but with the Magic Eraser, a quick wipe and it's gone.
Chris