Heat oven to 375�. Heat 2 tbsp oil in large heavy-bottomed skillet over medium-high heat. Add meat; brown on both sides, about 4 minutes on each side. Sprinkle liquid smoke over bottom of roasting pan. Place rack in roasting pan. Then place meat on rack; cover.
Bake at 375� for 1 hour. Reduce oven temperature to 250�. Bake for 3-4 hours more or until fork tender.
Meanwhile, heat remaining oil in small Dutch oven over medium heat. Add onion; cook 6 minutes or until softened. Add ketchup, chili sauce, molasses, vinegar, hot-pepper sauce, mustard, Worcestershire sauce, black pepper and water. Simmer for about 20 minutes, stirring occasionally. Remove from heat. Stir in lemon juice. When cool pour in bowl and refrigerate until meat is cooked.
When meat is done and cool enough to handle, pull apart into strands. Cut into 2-inch pieces and add to sauce. Return beef and sauce to Dutch oven. Simmer, covered, for 1 hour, stirring occasionally. Add more water during cooking if needed. Serve on toasted buns with potato salad.