For the record you can load a vape without nicotine. At that point it's just a mouth-operated fog machine. I think that's plenty of cloud for the effect, but Tom Scott certainly doesn't make it look impressive.

I'm sure it isn't the best thing for you but at least there isn't nicotine in it.

Removing lungs from the equation, Amazon does have this little guy that you could pipe up to a collar. Maybe an ultrasonic humidifier--but I don't think that will read particularly well.

How close is the audience going to be?