Put too much smoke oil in my bachman h0 scale engine, and it stopped running at all. Anyone have advice for fixing this? A bath in denatured alcohol? Dismantling and wiping out?

I just bought an old Bachmann  N&W J 4-8-4, not a new DCC one, and when it slows to a stop, you can often see a whisp of smoke coming from its stack. Did this train come with the ability to smoke, or it possible that this is a problem with dust or wiring overheating?

I'm leery of running it, until I determine whether I'm burning it up, or just need to buy some oil to make it smoke more...