We used to put a little Vicks in the vaporizer when we had a cold. It seemed to help break up the congestion. Your vaporizer looks a lot different than the one we used.
This might shed some light:
Looks like a gadget you attach to an old cast iron steam heat radiator to help humidify a room.
Didn't see Walter's posting before hitting the enter button. Interesting gadget. I wonder what the results of using one of those really was? Low octane fuel combined with moisture must have made a real mess in the chamber.