"Bless you" has always been a big no-no for Witnesses anywhere I've been, as well as "Good Luck". This past year though, one brother during a talk said that it was ok to say "Good Luck" because now it simply means that you wish the person well, you want them to succeed, etc. - nothing superstitious at all.... so why can't you say "bless you" then, since people today do not say it with superstitious intentions? "oh my God" is definetly something you don't usually hear JWs say - except for one brother who yelled it out at the beginning of his talk! (it was supposed to be coming from someone else, like he was telling a story). The whole auditorium went quiet - I think everyone was shocked! Needless to say, it didn't go over very well.