It turns out that according to an Italian dictionary, “fare il fiasco” used to mean “to play a game so that the one that loses will pay the fiasco,” in other words, he will buy the next bottle (of wine). That plausibly connects the word with the notion of “a costly mistake.” It sounds more plausible than the glass-blower mistake explanation.
I’ve been on a roll the past 5 weeks, got all those puzzlers. Which is unusual for me, I’m lucky to get even 1/2 of them. But I got all 5 of the recent ones, well, except this one. So 4/5. I was sure the word was “bogus”. Bogus seemed like it could be Italian for bottle, sounds quite a bit like “bottle”, and bogus does mean (in some sense at least) something faulty or of little worth. And “bogus” is a major go-to word for the brothers’ show too.
Alas, my idea was what was bogus! lol