Place ribs on a rack in a shallow baking pan. Sprinkle spice rub on both sides and massage in.
Brown in oven 10 minutes per side. You may need to turn the heat up to boril for a few minutes to get the brown. Drain fat. Place ribs in a slow cooker.
In a small saucepan, combine ketchup, hot pepper sauce, vinegar, brown sugar, honey, salt & pepper and onion. Bring to a boil and let simmer 5 minutes.
Pour mixture over ribs turning ribs until evenly coated. Cover and cook on LOW about 6 hours or until ribs are tender. Serve immediately.