Ha! Stick, where did you come up with this?
For years, I've read accounts of WD as a rust preventative, yet have personally observed the top of every WD-40 can rust, I've applied it to iron and seen that the object not only rusted but seemed to do so faster than I expected. I will say say that that rust has been light surface rust that seems to self-arrest.
same as you... VOE..
WD becomes Hygroscopic right after it dries... in it's liquid state it displaces water...
another thing I've found, WD is a dirt magnet...
think about it, the WD cans are painted too...
and I've made a lot of money as in bunches of, cleaning up after WD users...
self healing metals are either coated w/ or contain Aluminum oxide and/or chromium oxide
spray/soak the inside of a motor's distributor cap...
w/o letting the WD dry or wiping away any access put the cap back on and start the motor...
later you'll wonder why the cap cracked or came off of the distributor...
spring hooked caps'll jump and flash..