I've applied no-ox-id to all the rails on my layout, (all 200' of them) after vacuuming them, cleaning them with a track eraser, and using straight metal polish thoroughly cleaned off with rubbing alcohol. I also made sure all locos got a run over a section covered with no-ox-id, but then I got bored and left it overnight. Now, in the morning I cleaned it off by wiping 2/3 times until there was only a faint trace of black left on the paper towel. Fast forward a couple days and things aren't running as smoothly as I'd hoped, and if I run a paper towel over sections that have been run on, I get a lot of black stuff off. Is this due to improper cleaning? Perhaps not getting the metal polish off thoroughly? Or is it due to the locomotives having dirty wheels? Should I no-ox up my test track and give my locos a good run on it, since I don't have continuous running on my layout?