Funny, I've heard of a different superstition.I don’t know if this is true, but one of my teachers told me that “bless you” came from a Medieval superstition that if you sneezed, it meant you were possessed by a demon? Idk. I think a demon would have better things to do than make someone sneeze lol.
That when people sneeze, it's their soul trying to leave them, and saying 'bless you' causes the soul to get sucked right back in. XD Obvs an old superstition, but interesting there's more than one.
To the hiccups situation, I'm never around people I don't know who have hiccups. But to the people I do know - weather hardly know or know quite well - I usually say 'ahh, got the hiccups?' More of a rhetorical question, but I am around people whom English isn't their first language and may not know what it's called.
Then, if not busy I do try and find ideas that could help them stop it, cause I know how bad hiccups can be, I have them constantly! And it's a hatred I had so bad, because I sound so childish so I try and get rid of them quickly.
Usually holding breath (I can't really do that, makes me a lil sluggish), drinking water, or once I was able to get them away by angling my head downwards and breathing deeply.