/6 Cooling System: Multiple Cleanings

After much reading, I started using citric acid to flush while driving. I bought on ebay. Prestone used to use that, but their products seem wimpier today. I put a screen in the upper radiator hose to catch any debris. Seems to remove rust well. Did several in my fleet so far, when switching them to waterless coolant. I hate rust so much the cost is worth it to me.