Have used Bon Ami on old junk motors that smoked and new motors that had chrome rings. Just took the plugs out and blew it in the spark plug holes then reinstalled the plugs and ran the car hard to make the rings seat. Bought a 53 Ranch Wagon that ha sat for 10 years. Drove it from Cleveland,Tn to Jax. Fl. It used 15 quarts of oil ,but the more I ran it the better it got. After about 2500 miles it was down to a quart every 800-900 miles. You just need to drive the crap out of it to force the rings to seat. Don't baby it or it will never happen.