Place ribs in large roasting pan (cutting racks in half if necessary), cover with warm water (the ribs should be completely submerged), and sprinkle with sea salt. If desired, add chopped carrots, celery, or onions.
Cover tightly with foil, and simmer in the oven for 3 1/2 hours.
While the ribs cook, prepare BBQ sauce: measure ketchup, brown sugar, vinegar, chili powder, and molasses into a mixing bowl.
Add the orange zest and juice. Whisk well.
After 3 1/2 hours, check the ribs. A sample bone should slide out cleanly with a firm tug (if not, cook ribs another 30 minutes).
Move cooked ribs to a baking sheet, and brush both sides generously with the fresh BBQ sauce.
Let them rest for 30 minutes to absorb the sauce (save extra sauce for another time).
Last, put ribs on pre-heated BBQ, using both tongs and a spatula to keep them in one piece.
Grill just long enough to get grill marks and heat the ribs through.