Instead try this: Say "What?" And stare at them. Wait for them to explain. Act as though you do not know what a sneeze is. Allow them to explain the process of a sneeze. Tell them you have never experienced that in your life. Wait for them to get exasperated then in a dismissive way mention that you aren't sure you believe them, and change the subject.

Congratulations, you have won this interaction.

I always say “shut up” in the most annoyed way possible.

I don't see anything wrong with gesundheit. It means health. And really I feel like the German expression is just saying - be healthy dammit, and stop sneezing!

Gesundheit

Nice Ron!

This was covered extensively on an episode of Seinfeld

"I hate when you do that"

That's my favorite

sneeze once "Bless you."

Sneeze twice "Gesundheit."

Sneeze three times "Ok now you're just fishing for attention."

"Satan curse you"

“I’m sorry, I didn’t quite catch that.” - in a Siri voice “Nah, I’m good, thanks though.” “Dude! You scared the crap outta me!”

Ashley Johnsons reactions to Sam Riegels sneezes

I always 'shhhh' like a librarian would

Curse you.

In Greece we say "Γείτσες", which is a dimunitive for "Υγεία" (=Health), so essentially its like wishing the other person to be healthy.

I like to say GOD BLESS YOU in the most dramatic exaggerated way possible immediately after I sneeze so I beat everyone to the punch. You can't bless me bitches.

"Well done" and "clean that up" are my favourites

Sneezing isn't normal! I never sneeze.

In Dutch you can say "you sneezed"

Sneezing isn’t normal, I never sneeze

get any on you?

I always tell my partner to cut it out when they sneeze.

"I disagree"

I like to say “acknowledged!” like Picard

I prefer the simple "Curse you."

Ew

Yuk

"Heard, chef"

recently, schatzi asked me to stop saying gesundheit or bless you or something each time she sneezes because it triggers her to sneeze again apparently...

I say "god damn you" to unwork the broken blessing system.