Chemical Cleaning
WARNING: This page is about a different car, the 2008 Dodge Magnum, 2008 Dodge Charger, and 2008 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.
In some instances, use a radiator cleaner (Mopar Radiator Kleen or equivalent) before flushing. This will soften scale and other deposits and aid flushing operation.
CAUTION:
Follow manufacturers instructions when using these products.