I was thinking that a couple of #30 holes drilled at the top of the threads could allow the last 1/8" of oil to drain out just fine and it wont affect the plug in any way. Just make sure you run a wire brush across the holes to de-burr them.

A true optimist, changing oil without changing clothes first. Lots of "Exxon-Valdez" opportunities. I was always prepared for that, and usually got it, changing the oil in the 914-6. Hard to do it without a mess since there was no drain plug in the tank and you had to split a union in the oil return line to drain it. So the oil came out more or less horizontally!

I love this story. I can see you trying to clean up the mess before being busted by the wife. I think we have all be there before.