the pins and all that mech in the lock can rust, so dont be so denying that No, Even thin oil, be introduced.

[ my AXA ring lock, stays in the key in the lock to ride , mode,

though I have a piece of shock cord, and a spring toggle.

that keeps the key on my wrist when I lock up the bike,
and looping the cord over the rack strut , when the key is in the lock.