Convalesce You
Think of "Convalesce You" as a secular alternative to the customary "God Bless You" or "Bless You" one might say in response to another's sneeze. "Convalesce" means to recuperate, recover, or regain one's health. Saying "Convalesce You" (rendered as a 3-syllable con-vless-you) in response to a sneeze satisfies the social norm of not disregarding another person's sneeze, without invoking any Gods or representing any authority to confer blessings.
AHHH AHHH AHHH CHOOOO!!! Convalesce You!