As an aside, all these upper cylinder products may work out just fine at doing whatever they claim, including those old pellets. I don't intend to demean anyone's efforts or talk anyone out of using them.
But while I'm no chemist, I just think some of the chemistry appears to defy basic principles from time to time - like how they keep these heat-fusing metallic materials out of the ring lands.
I guess in an old beater already staring at a major upper cylinder job, tossing $20-$30 at it with one of these products is rational, if only to experiment on the cheap.