After-Run Oil - is it useful?

Some research into the topic which might help decide what to do (given lots of conflicting information out there):

• An excerpt from the Traxxas (R/C car) engine manuals which recommends just using WD-40: "When a nitro engine is shut off, some excess unburned fuel remains in the engine. The methanol in model engine fuel is hygroscopic, which means it easily attracts and absorbs moisture. This moisture can cause rust and corrosion on the steel engine parts (crankshaft, bearings, wrist pin and starter shaft) if the fuel is not removed from the engine. There are after run oil products available from your hobby dealer or you can use WD-40™, a common household lubricant."

• After run oil article (one person's opinion on the topic)