Me Iam a Prestone guy and use their flush and their antifreeze with 50-50 distilled water. NEVER failed me and I even run with the presure cap loose so there is not pressure on the system. I dont like the accordian pressure effect of going 0- 17psig every time I start the car and then 17
-0 when it cools.

Me Iam old and have replaced my share of heater cores and soldered too many radiators after I rodded them -- you dont wanna know what that is.

Remember clean is next to impossible and

Clean is invisible

Woody