Back in the day when I was listening to my advanced flight/building instructor I had to hear the same argument over and over about the use of after run oil.
His statement was: The alcohlol evaporates almost right away from inside the engine, after that what is left inside??? Oil!!
OK, true statement and to proove A point, I was given A big bunch of old engines by this man last year and these engines were run, shut down, removed from the plane and tossed up on the shelf.
After all these years all I have done when I needed one of these engines is to heat it up with my shrink gun, take it apart and clean up the nasty gunked up Castor oil so it rolls over smoothly and fire it up and tune it. NO rust has ever been found in one of these and all the bearings were in fine shape.
My feelings about it are simple, if it makes you feel better then go ahead and use the stuff, as long as it's not A YS then it isn't really hurting anything. I use it on rebuilds and I clean out my own engines with Alcohol then hit it with some after run oil if I'm not going to use that engine for A couple of years. I don't know if it helps or not but it makes me happy doing it that way.