Whoa. This time its not just a different version of the story (as it was with the gefilte fish on the train), but you’ve also made an important mistake.
Zechs und neinziger (one brand is Everclear) is 95-96% alcohol, not 96 proof. It is 190-192 Proof.
As for the story, the version I had was a little different. A older gent refused to drink anything but pure zechs und neinziger. His friends and relatives told him he’s crazy, it’s too strong, and that drinking it will kill him. He would reply that if anything, it’s not pure enough and that he wishes it were 100%. On the day he goes to the doctor and learns that he is afflicted with water on the lungs he says, “Oy, I alvays knew dat 4% vas gonna kill me”.