RE: oil War
The cleanest "burning" oil is no oil at all. Never any exhaust oil residue that way. However, if having no residue to clean up is the most important thing, plan on taking many engines to the field with you every day. You'll get from 10 minutes to 30 minutes out of each one before they become melted slag.
Personally, I'll deal with a little clean up, which is far less than one would deal with after a .40 glow engine flight. Normally it takes a month or two of flying my planes with a 50-1 mix before I even consider wiping them down. Really doesn't matter which oil is used.