Cleaning oily gunk out of the cooling system

[ngoma]

Head gasket failure allowed engine oil into the cooling system. I guess that proves that oil pressure is higher than cooling system PSI . Actually I prefer that to coolant in the oil .

But it is a mess to clean out. Oily black coating all the interior cooling system surfaces. It will attack the rubber hoses and gaskets, and reduce the efficiency of the cooling system.

The cooling system flush products available today are not very effective on the oil mess. I am intrigued by this method, the one they call the 3 Day Power Flush.
It involves a bucket, sump pump, and extending the upper radiator hose into the bucket, and the sump pump discharge into the upper radiator inlet, letting the pump circulate the water + cleaning agent (I am thinking automatic dishwasher detergent) thru the cooling system for 3 days.

What do you think?