I have never visited a hot dog factory, but I have been warned against it by people who refuse to eat hot dogs afterwards. Apparently, lots of stuff can go into a hot dog, and none of it looks like something you would slap on the grill, so the input does not match the output. I rarely buy hot dogs because I ate too many in college. (Seriously, the cheap ones were sometimes four packages for a dollar!) Nevertheless, toss a few on the grill, and I still find them hard to resist. Something about animal lips and mustard!