>>
>>The idea isn't totally off base, just too weak to be effective.
>
>
> not do concerned with the corrosion, more about the dex cool coolant mixing
> with the residule in block


That's simple. Flush with straight water first (fill, start, warm up so
water circulates, shut down, and drain immediately. Then throw away any
DexCool you have, and put in Ford or Mopar G-05 coolant instead. And use
distilled water.