I just read this thread for the first time. Man, that is some amazing damage to that engine caused by a small piece of ball bearing. [X(]

As for ARO and MMO, I have used MMO as an after run oil for as long as I can remember. I used to use it straight. Then I started mixing it 50/50 with ATF. Recently, I have mixed it 50/50 with Mobil 1 synthetic motor oil. Each brew has been more slippery than the the previous one. As for drying up, well I just opened a coffee can with an engine in it. I stuck this engine in the can in 1978 and poured in some stright MMO to cover the bearings, cylinder, and crank base. After 30 years it looks like it has evaporate maybe an ounce. And except for the threads on the tip of the crank, I don't see much rust.