RE: After-run oil question
If you are running a non pumped engine (not YS engines) then any air tool oil will do or Rislone engine treatment. Both can be found in Walmart and a whole quart is usually less than that little bottle of the hobbico stuff that Dr Nitro suggests is Marvels Mystery oil.
Make sure you run your engine dry at the end of the days flying or driving and squirt in a good amount and spin the engine over to distribute the lube. The products listed work very very well and have been proven over many years by many modelers.