Preheat a barbecue for medium heat then lightly oil the grate.
In a bowl, mix together the all purpose seasoning, black pepper, garlic powder, onion powder, paprika, Worcestershire sauce and smoke flavoring until thoroughly combined. Rinse pork chops then sprinkle the wet chops on both sides with the spice mixture. With your hands, massage the spice rub into the meat; allow to stand for 10 minutes.
Barbecue the chops over indirect heat until no longer pink inside, about 12 minutes per side. Allow chops to stand for 10 more minutes before serving.
Liquid smoke is a flavouring that has really taken off lately. Use it to add a smoky BBQ flavour to any meal.