These guys are shilling, with this voodoo stuff to suck in the gullible, who have no idea about AC (alternating current) mains theory.
They are relying on "expectation bias" (+1 Ralph) with the gullible not to send the 10c fuses back for their $100 refund.
Even if 50% are sent back, that a hell of a profit still, then that 50% gets resold, not even as used stock, eventually all are sold, with a massive profit margin in the end.
Quick way to make a fast million with very little outlay, probably even better than getting in on the ground floor of Apple shares.
Cheers George