Electrolysis happens whenever there are 2 disimilar metals in contact with each other and a liquid touches both of them. There is a flow of electrons between them as the tiny electrical charge between them tries to neutralize itself. The metal with the stronger negative charge dissolves slowly because it loses electrons until it reaches the point that it is too weak to be useful. It is a normal situation most often seen in boats used in salt water. The electroplating process is the same thing except that it is forced by using DC current to speed the process. About all you can do is check for the PH value of your AF mix. It should be as close to neutral (7) as possible. If it is strongly acidic or basic it will speed electrolysis in the engine and cooling system, radiator included.
I am rebuilding my tranny at the moment and snapped a pic of my rear freeze plugs for everyone to see. Note there are 2 in the block (different sizes) and 1 at the back of each head. Mine has not started leaking yet...but while I have the tranny out, they are getting replaced.
