What did Hitler say while filling up his car? I don't use this kind of gas.
I'd like to know if that's supposed to be a Holocaust joke.
No, it's just a statement which is true. Everyone knows very well what happened to "inferior races" in the 1940s.
I think that's a very anti-Semitic thing to say. It isn't right to call Jews or anyone else inferior, and it isn't right to joke about Hitler or the Holocaust. Watch some documentaries about World War 2, maybe it will help you to put these things in perspective.