As far as the brilliant pebbles, weight loading components is pretty well excepted as a tweak that can sometimes have a positive effect. I haven't bought the pretty rocks or other expensive means to do this, but I suspect that some folks have used the pebbles to good effect. The other stuff I would not spend my money on, but what is and ain't snake oil in ALL applications is hard to be absolutely certain of. In example, to my ear and in my system, power cords are snake oil but others have found them to be capable of creating a positive effect.