Exactly the same way as Nietzsche did not create Nazism. He may have treated Jews rather badly in his books(the worst parts were apparently put in by his sister, a real nazi) but I think he treated the christians if not worse, then at least as bad. It is sad that symbols and ideas now are "forbidden" because they were used by the nazis.
Noone in Norway dares to use neither runes, nor St Olav's cross (used as symbol for the norwegian nazi government, Nasjonal Samling), which I find a great loss; these are parts of our culture and history that were stolen and sullied.
But I'm off topic here. Concerning Wagner, I must say I'm not a great admirer of his music; I feel far more drawn to Chopin, Grieg and Beethoven. But I would truly love to see one of Wagner's operas, which I've been told are incredible when performed live.
to Nietzsche's old credo "live dangerously" I have always responded with my "live cozily"