Remove silver membrane from the back of the ribs. Massage dry rub into ribs, front and back.
Pour water in bottom of slow cooker. Place ribs in slow cooker, followed by garlic and onion.
Cook ribs on high for 4 hours or low 8 hours or until ribs are fork-tender.
Turn oven to Broil. Combine ketchup, chili sauce and barbecue sauce.
Brush ribs with sauce mixture and broil (or grill) 3-5 minutes or until charred.
Notes
Rib Rub: 1 Tablespoon paprika, 1 Tablespoon brown sugar, ¾ teaspoon garlic powder, ¾ teaspoon onion powder, ½ teaspoon black pepper, ½ teaspoon lemon pepper, ½ teaspoon salt or to taste