There is an additive, TCP $35/qt, which aviators use to reduce lead fouling on spark plugs.
It seems that our experiences differ with your being aircraft and mine being more ground based and we may both be right. And I apologize, I was a little short with you and that was ignorant and rude of me. But at the time we were talking about getting gas for old cars, lawnmower and chainsaw engines. Chainsaws absolutely love av-fuel! Most lawnmower and chainsaw engines don't get far enough off the ground to have the rich fuel mixture and cool head temperature issues that a piston driven aircraft might suffer from due to thin air at altitude and overly effective cooling from lots of cold thin air blowing past them. That can cause all sorts of buildups internally. Incorrect fuel mixtures will cause far more engine problems than just fouling plugs. I suspect that the reason that you were burning through plugs on your old car was that you did not have enough octane for the compression and timing advance of your engine. That's not to say that the octane was not right for the compression ratio though. Many factors come into play, fuel mixture, ignition timing engine temperature as well as compression ratio. They must all be in harmony. To much timing makes an engine perkier at some rpms but if the advance curve does not match exactly right and the engine spark gets too far ahead of itself, that causes damage. Even a little corrosion inside of a distributer can cause such a problem. If you saw little grey balls on your plugs, that was not lead. Those were melted parts from the top of your piston from "pinging" or detonation. That would also be consistent with going through plugs like crazy. I imagine that your plugs ran kind of gray instead of a nice tan color. I will agree with you in part about consuming gas by breathing or drinking it by quoting Mel Gibson when he, playing Marten Rigs, and yelled "Yuck! Ethyl!" (short for tetraethyl lead) while siphoning gas.