RE: Black goo
Edwin,
Did you try the mineral spirits yet? My workbench is painted with WBP and I use mineral spirits on it all the time. Has always worked great for me and it doesn't touch the paint. As you say, alcohol acts as a mild solvent on WBP.
I agree with whats been said about the oil amount. Even at twice the normal amount, the engine would run just fine (though the needles would be off a bit) .... the extra oil would tend to just wash out the carbon in the engine and muffler. Maybe thats what you mean by "goo?"