I have a Bachmann 0-6-0 with a smoke unit on a very small display unit. My grandson likes to see the locomotive smoke so I use the liquid smoke when he's around. Sooner or later, I have to clean the track with denatured alcohol on an old T-shirt as it will start running poorly because after the smoke goes up, it comes down on the track. I also have to clean the drive train on the 0-6-0. We use the same denatured alcohol to warm the fondue pots. Hmmmm, I wonder (since it is flammable) if it caused the sparks on the track when the train was running after a clean-up?