ORIGINAL: KW_Counter
If you use fuel to clean the engine then clean the fuel off with alcohol when finished.
The nitro-methane is corrosive.
Reassemble the engine and put some after run oil in it.
Substitutions for after run oil are Marvel Mystery Oil, Automatic transmission fluid or
(I've heard) brake fluid.
KW_Counter
Brake fluid attracts moisture. It is also corrosive. Not good for glow engines.
When my engines, and engine compartments get all oily and gucky, I hold the plane over a garbage, or better yet outside, and hose her all down with pressurized ether. That's 'starting fluid' for those that don't know. Works great, cuts the crud, and dries without any residue.