I don't think any such list is complete without mentioning Voluntary Tubal Opening, or béance tubaire volontaire (BTV). It takes some training, but if you figure it out it's much more direct, not to mention more direct and safer than some of the other methods.

I'd call this a duplicate, and more of a rant than an actual question. But assuming the point was to get answers and not just rant about airlines, maybe break it up a bit and ask a specific question rather than "how could they do this to me?"

@Willeke, I can't believe this claim either. I think you need a citation, not just "you can find it on the internet"

Actually I'm still confused; I suggested an edit because I thought you were talking about damaging the converter. But it seems pretty clear that you mean using a converter will damage the device. I'm not really sure what scenario you are imagining: are you saying they shouldn't convert 220 to 120 to run a 240 volt device?

I suggested an edit…

Oh, the converter will be damaged? Sorry, I get confused when there are ambiguous pronouns kicking around. I got confused because it in the previous sentence refers to somthing (not the converter). Maybe be more specific?

Am I the only one who finds the third paragraph confusing / contradictory? It will certainly run on 220, you shouldn't convert the voltage, but oh yeah, it may be damaged? Um, so maybe I should use a converter?

Also, for the few devices that do require a transformer make sure you check the input power. The transformer for that 1 kW hairdryer is going to be an absolute beast in both size and price, you're probably better off buying a hairdryer for the country you're traveling to.

@immibis, as a few people have pointed out, you never be unsure. Every electronic device I've seen has the input voltage stamped on it somewhere.