We were visiting friends in Ohio and they were having family over for a hot dog cook out. I was with them at the grocery and when they did not buy chili, I grabbed a can of chili(ugh) on the way out. They asked why and I said the only way I ever ate hot dogs in SC was with chili, onions and slaw (and a sliver of mustard).
Sure enough, check out the Carolina Dog.

One trick I learned was to put all the stuff on first and then the frank. Get more on it that way and it doesn't spill out as bad. It is lunch time and a new hot dog place just opened near me. Headed out now!