For glaze, in a small saucepan combine catsup, molasses, lemon juice, soy sauce, and crushed red pepper. Heat and stir until bubbly. Cool, cover, and chill for up to 5 days.
Cut the ribs into serving-size pieces; place in a Dutch oven. Add enough water to cover ribs. Bring to boiling; reduce heat. Cover and simmer 30 minutes. Drain ribs; cool slightly. Season ribs with onion salt and pepper.
To grill ribs, in a covered grill arrange preheated coals around a drip pan. Test for medium heat above drip pan. Place precooked ribs on grill rack over the drip pan, but not over the coals. Cover and grill for 45 to 50 minutes or until ribs are tender, brushing occasionally with glaze during the last 10 minutes of grilling. Heat the remaining glaze on the grill or stovetop until bubbly; pass with ribs. Makes 4 servings.