A while back, there was a guy at Umaine selling a fuel additive that was supposed to double your mileage, make your engine purr, reupholster your seats, etc. etc., but the local TV did a report on him and it turned out his additive was: I #$%* you not.... used oil, milk, and sawdust. It looked like a protien shake.
Strangely enough, it didn't work! Crazy right?