It's wild how many people will use a harsh chemical because it's handy, without checking if it's safe for the material. You see it all the time with cleaning products too, where something strong enough to eat through a finish gets used on a surface it'll ruin. It seems like a general habit of grabbing the quick fix without a second thought. That kind of shortcut can get really expensive, or worse, when you're dealing with something as critical as an aircraft part.

Yeah, vinegar is great for rust, but calling it a "household product" is a bit of a stretch for this use. It's a mild acid, and leaving it in a frame tube for two days is basically a chemical process. For something less involved, like a rusty chain, I've had good luck with a coke soak, which is also acidic but maybe a bit safer to mess with. You just don't want to get in the habit of using food stuff on bike parts without knowing what you're doing.