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.
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!
I started saying "Gesundung" as a joke 10 years ago, and now I can't stop. It's not a real word, but if it were it would mean "Getting healthy". Seemed more appropriate to me at the time, and still kinda does.
It feels very good, like physically itches the inside back of my throat (amazing if you're having an allergic response to something), while being deeply psychologically satisfying to yell from your abdomen. I try to only do it at home, but there's a reason some people scream-sneeze.
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.
"Don't you dare ask God to help me," Crawford reportedly snapped at the nurses praying at her bedside, before moments later the Academy Award winner took her final breath.
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...