the smoke machine

Different smoke machines get filled in different ways. I have never seen a smoke machine like that one. I think it was just a prop with a real smoke machine behind the red-painted wall of that set. Personally, for a dream sequence, I would have gone with a floor-covering dry ice fog, but then, those rigs wouldn't ever catch on fire, so, that wouldn't have worked all that well for this flick, nor would it have been all that safe to catch a real smoke machine on fire.... so, again, probably just a prop.

Most smoke machines, and ALL indoor varieties are electric-powered. Confusing the fuel and fluid fill caps wouldn't really be an issue, but in reality equipment does often show up on a set from a rental house that no one on set is familiar with- and mini-confabs to figure out how a piece of equipment works do really happen.