I got it back in last week and finished the job although with only half of it replaced, I feel the correct way to do this is to empty the system and fill with straight distilled water, get up to thermostat opening temperature, let it circulate, then drain. Again won't get it all but will dilute out whatever is in there. Theoretically I will be down to 1/4 of the original at that point. Do it a second time remove half, leaves me at 1/8 / original nominally. 87.5% is good enough for me. The only issue is where to dispose of the tens of liters of coolant tainted water. I can drop it off at a hazardous waste site and I will or maybe my local mechanic will take it. Right now I have three 5 gallon mobile one containers with used antifreeze and no other empty containers until I change oil in the escape again.

Blah blah blah. I assumed at the dealers just hook up a machine to the reservoir and push water w the thermostat open until it comes out clear.

I had asked before in a post that I later deleted whether or not I could use a coolant system pressure tester to create positive pressure at the reservoir to help push coolant through the system. The idea sounds fatally flawed. Was hoping someone could tell me why. With the petcock closed it is a sealed system so I should build pressure regardless of where the reservoir ties into the system.