After spreading a fine film of graphite on each of my ignition keys just as a "precaution," my dumbass brother/wrench has caused the ignition switch not to turn.

Would something as ridiculous as graphite cause one of the tumblers to stick? Or is this something related to a steering wheel lock gone bad???

Anybody ever have this problem before?

Car is an '89 190e 2.6

Need help.