The problem with mercury paste or other such sabotage tricks is that a commando has to touch each aircraft...when much better solutions were available such as spiking the fuel in the depot in order for a single commando action to take out an entire squadron...sometimes more.
Planes were often well-guarded...fuel, not always so.
Planes were well-guarded against sneaky guys putting bombs in them, or knocking parts off with axes or chainsaws.
That was less the case for a mechanic or mechanic's helper, who could be wiping the mud and debris off landing lights or taping over the gun ports, and in the process casually *wipe a little corrosion away* from a propeller spinner or blade.
The guy who told me the story was my airframe and powerplant mechanics instructor, who had formerly held Braniff Airlines ID card #3, hired as a mechanic even before the Braniff boys started hiring pilots. During WWII the OSS had consulted with him and some other folks, including tech reps from the Hamilton Standard propeller manufacturing company, to determine both the best means for those in occupied territories to sabotage German aircraft and what we should be most wary of.