The only part of pigs humans do not eat...are the oink oink's.
True. I remember ordering a meal at a restaurant in NYC's Chinatown — "456" — and they had something called "pork muscle". Sounded good from the written description. I asked the waiter what it was and got an unintelligible response. I figured, what the heck, and ordered the dish. The pale meat was very "chewy" and circular in shape with an open center. I figured out that it was pig's intestine.
I'm one of those "cast iron stomach" guys and wolfed it down, but I was careful not to reveal exactly what I was eating to everyone else.