All you need is enough spark to ignite the mixture. More spark than that *if there is more* doesn't give better burn propigation.
I've seen similar items many times. Most are just an additional spark gap in series. ie: Nology.
If this was the greates thing ever NGK or Champion would have bought them out, and these plugs would be in EVERY new car today.
99% of the gas saving gizmos out there either don't work, or actually use more gas. Don't drink the Kool-Aid.
John C.