I don't know if he's right or not but he could be. Electrolysis works more like a battery, remember your simple science?

You need two "dissimilar" metals and an electrolyte.

a lemon, a dime, and a penny make a battery. It might just be that the radiator, the block, and the antifreeze are causing this. It's been a long time, but big trucks used to use sacrificial filters and additives to help prevent this, and if it's this bad, Chrysler should be doing something with it.