If you have to sneeze, I know that you should:
a) Leave the dining table
b) Use a hanky
c) Wash your hands, if at all possible.
Should you say anything immediately after you sneezed? I mean beyond excusing yourself to go to the restroom.
FH and I had an etiquette argument yesterday. I was driving the first leg of a long trip. I sneezed. I commented that he never said, "Gesundheit" or any equivalent. He said he waits for the sneezer to say "Excuse me." Which makes completely no sense. We then had an argument, I left out some of the incendiary stuff. I did a book and internet search, and the only thing I learned is that you can stop a sneeze by pressing on your upper lip.
Generally, his manners are wonderful because his mother is a gracious woman who whacked the backside of his head when he was rude.