Preheat the oven to 200°F. (See Kelly’s Notes.) Arrange two large pieces of foil on a baking sheet so that it hangs off on all sides.
In a medium bowl, whisk together the Lawry’s Seasoned Salt, garlic powder, pepper and brown sugar. Sprinkle the ribs on both sides with the spice rub.
Place the rib slabs side-by-side on the foil then gather the foil up and over the ribs to make a secure foil packet. Pour the liquid smoke and water into the bottom. Place one more piece of foil on top and press together the edges to seal the foil packet.
Bake the ribs for 5 hours.
Remove the ribs from the oven and remove the top piece of foil. The ribs are done cooking when they have reached an internal temperature of 190 - 200°F.
Change the oven to broil.
Brush the ribs generously with barbecue sauce then broil them until the edges just begin to crisp, about 3 minutes.
Remove the ribs from the oven, brush them one more time with barbecue sauce, then serve.