Pat the ribs dry with paper towels, then season on all sides with the salt. Place the ribs on a sheet pan. Roast for 8–10 minutes, or until the meat is browned on the bottom.
Meanwhile, place the bbq sauce, water, worcestershire sauce, apple cider vinegar, and chopped onion in a slow cooker. Add the browned ribs, and stir to coat.
Cook on high for 2 hours, then turn the slow cooker to low and cook for 3–4 hours. The ribs are done when they are tender and starting to fall off the bone.
You can also cook them on low for 8 hours.
Notes
You can make this recipe with either bone-in or boneless country style ribs. I used bone-in. These ribs reheat very well. You can reheat them in the slow cooker, in the oven, or in the microwave.You can freeze any leftover ribs (including the sauce) for up to 3 months.