- Make a slash on the inside of the chicken wing joints without cutting through the bone and in a few other places.
- In a large, shallow baking dish, combine the ketchup with the mustard, hot sauce, soy sauce and brown sugar.
- Add the chicken wings and turn to coat. Cover and refrigerate overnight.
- Light a grill. Remove the chicken wings from the marinade, leaving some of it on them, and reserve the remaining marinade.
- Grill the wings over a medium-hot fire, turning and basting them with the reserved marinade, until nicely charred and cooked through, about 30 minutes.
- Stop basting during the last 5 minutes of grilling and discard any remaining marinade.
- Serve the wings hot or at room temperature.