I would imagine that this stuff would actually work for a very short time - it will set around worn rings and scratched in the piston and probably give you a great performing engine untill it all starts to burn off and break away.
A bit like putting saw dust in a noisy gearbox to deaden the sound.
Probably a great idea if you have a nackered engine - treat it with this ready for when you sell it
(hmm dont suppose any one will ever buy an engine for me ever again)