Imagine that, a Sunday mail delivery!
I thought my rails were clean until I drove the Intermountain FP-7 and pulled the new CMX around the ovals and passing sidings a few rounds. That’s all it took to make the cleaning pad black where it touched the rail heads. I was using automotive laquer thinner as a first time cleaner.
I had one problem with it though. The supplied syringe locked up and would not budge about half way through the fill stroke. Prior to this I had filled (and emptied) the tank with isopropyl alchohol to flush it out. I finally wrestled the plunger out and dried it quickly with compressed air. It seems all right now.
So, if you use laquer thinner or MEK etc., find another way to fill the CMX’s tank.