soundslike your idea on the radiator is ok, for me I never belived in putting anything in it,,you might use some type of pressure hose to help blow out the rad. from the outside of the cores and then do the garden hose bit,,, with that twisted off plug, you might do a search here,, some have talked about it but dont recall who,,,maybe just drill it out, put a screw/bid and get it out that way,,,good luck,,Fred
