Sauté onion and celery in butter in a medium saucepan until tender. Stir in dressing, water, salt, and pepper. Remove from heat . Spoon mixture into pockets of pork chops, and secure with wooden picks.
Place coals to one side of covered grill; when coals are grey-white, sprinkle with hickory chips. Place chops on opposite side of grill from coals for in direct cooking; cover grill . Cook chops 1 hour or until well done, turning chops and sprinkling with liquid smoke every 15 minutes.