Antibacterial Metallic Ion Effect?

When buying new supplies for the yeast garden I was faced with a choice to make... 20 meters of regular aluminum foil for a buck... or 10 meters of "Antibacterial Aluminum Foil" for the same price.

The packaging notes that the product contains no chemical antimicrobial agent and has no effect upon any bacteria not in physical contact with the foil.

Humm...

Does that mean it is just plain aluminium foil, and all aluminum foil has an inherent antibacterial activity?
Did I just get 10 meters less product - because I wanted the good stuff?

Was I duped?

Anyone know anything about this sort of product/advertising,
or a mechanism of action?

Dunno if it works or not, but I would've just gotten the regular aluminum foil, and spritzed it with a bit of starsan. The claims sound like something from an infomercial, and unless Vince from ShamWow was selling it, I personally wouldn't get it.