The Mad Lab

Anyone out there have experience making props that smoke? Not props like a dragon that could use a regular fogger - but props like handguns or backpacks.

Basically, I was considering how to make steampunk stuff more "steamy" by adding smoke such as might come from a coal furnace - or steam from an engine.

Ideally, the solution would be battery operated so it could be portable / wearable. I would also like it to puff intermittently like a steam engine, though continuously might work sometimes too.

I have been looking at "smoke units" for model trains. These appear to use solutions similar to those used by foggers. They are powered by the track - usually at least 15 volts. Has anyone out there actually used one of these units for a prop other than a model train? Any advice on brand, sourcing, or modifications?

Anyone have a better idea maybe? I think it would be pretty cool to see steam coming from a steampunk ray gun, or to make my steampunkins actually look steam powered. I just don't know the best way to do it. If the internet has taught me anything, it's that whatever the idea, someone else has already had it and probably done something with it. I'm reaching out to my peeps first.