Hi FlyerRich,
Many thanks for the information! I was concerned that it might have an adverse effect on the plastic wheels of the rollingstock, but what I will do is apply it then run just the loco and tender (all metal wheels) around until the excess has dissipated. For the past few decades there is always sparking from the tender's wheels. Most of my track is circa 1952, and the train is also that age.
Take care, Joe.