I flushed out my CA just using auto radiator flush. To rinse it out I ran the water in and opened the drains on block and radiator. Keep radiator and block full of water. Rinse for about an hour with motor and water running. Then turned off motor and drained it dry. I then used SW sealer in radiator and block to seal up leaking head gaskets, etc. Again following can instructios. Added anti-freeze.