We are flying and you are right: I didn’t know (and wouldn’t have guessed) that residual fuel smell alone would be enough to result in possible confiscation. Thanks for yet another tip I can add to my notes!
ya, you really have to be super careful about any smell.
The last few times Ive flown with my Trangia, I've washed the stove (which is a glorified fondue burner sort of thing) itself out with nice smelling liquid soap, to be sure to eliminate any alcohol smell, as with the bottle I was taking to put alcohol into.
It would be a real pain to have to find and buy a new stove at the start of a trip. Even back in the 90s when I first started flying to bike touring destinations, I wouldnt take my liquid fuel stove, but borrow a propane type that uses the blue screw on containers, as the actual stove part would never have any smell (I probably opened the valve or anything to let it completely air out to really make sure there wouldnt be any chance of propane smell).