I visited Auschwitz Birkenau and I don't remember there being a snack bar or any hot dogs.  When you say "they sell hot dogs at the Auschwitz snack bar," are you saying that the state museum owns and manages said snack bar or are you saying that there happens to be a random snack bar away from the camps that sells hot dogs before you get on a tour bus to visit the concentration camps. 

Auschwitz is also the German name for the Polish town where the camps are located, Oswiecim, so perhaps you're suggesting that no snack bar in the town should sell hot dogs?