Although I grew up on Noo Yawk Dogs, the Chicago ones sound mighty tasty too. My great-great-grandfather, coming to Chicago from Germany, discovered slaughter-houses were discarding piles of beef intestines and made a deal with the meat companies to haul them away. He turned them into sausage casings (presumably after cleaning them well) and made a fortune. This was back before hot dogs were packed in plastic and, as is the case today, merely pressed and held together with gelatin to keep their shape.