Not sure what it can out of, but it surely can be cleaned up and reused without issue. Where did the oily looking threads come from? If you have a bench grinder with a wire brush on it, clean that plug up, re-gap it and it should work good... You can even take a small points file and flatten the electrode some if you want and re-gap and install... I have some spark plugs in yard equipment that I personally know are over a decade old, but they crank and run perfectly so I'm not going to change anything without reason. JMHO!
