This guy is an idiot pusher for seafoam ! In the 1st place I saw very little difference tween the 1st and 2nd. And some....if not all of us know that just plain water does the same thing, and probably better. Water is what dealerships always used when an engine had a piston noise suspected of being a carbon knock. And I have stood right there and see the noise go away. They held the throttle wide open, and control the RPMs w/ the water quantity.
For $9 I'd have expected something,....but then, most of us are not surprised I'd bet.