Preheat oven to 350 degrees. Make several slashes along the surface of the pork butt. Rub with salt, then liquid smoke. Prepare ti leaves by removing the rib. Lay out a large piece of heavy-duty aluminum foil, and place 4 ti leaves on top. Place pork on leaves and wrap them around the pork. Cover with remaining leaves in the opposite direction until pork is completely wrapped. Wrap the foil tightly around the pork to make a watertight seal.
Place package in a large roasting pan. Fill with two inches of water and cover pan tightly with foil. Bake at 350 degrees for 1 hour. Lower temperature to 325 degrees F and cook for 3-3 1/2 hours or until tender. Unwrap pork from package and shred before serving.