I looked through many entries you posted about using Citric Acid as a cooling system cleaner back to around 2000. Some just said to use Citric Acid. Some said to use 1 pound of citric acid per gallon of distilled water, while others said 1 pound of citric acid per 3 gallons of water. More than one, but not the majority, said to use Shout before using the citric acid, but none said what proportion of Shout to water. And one said to neutralize the system with baking soda after using citric acid. What is your current magic formula for a clean cooling system? I haven't serviced the cooling system in my '52 GMC 228 in six years and I'd like to use your method.