I use distilled water and Red Line Water Wetter.
www.redlineoil.com. It is supposed to help with corrosion, rust, lubrication and keeping the engine running cooler. I also use it in my dirt bike. I picked it up at the local speed shop.
We used Nalcool at work in our diesels for years to help with electrolysis. Now I think the
antifreeze takes care of it.
Scott