I guarantee that, were the need for brain-devouring zombies to become pressing, you would make great strides in zombie development - or you would perish and your fundamental information (genetic and memetic) would be lost to history. As it stands, you probably have more drive to order pizza, or surf the Net. Were these things removed, you would find a way to get them back - a necessity. And were flesh-eating spawn of darkness the best way to do so, you would presumably be more motivated to spawn them from darkness.
But I'm willing to guess you don't really need zombies yet. When you do, well, I'm aware of a few methods that could be used (plastic surgery and a rare Caribbean root are vital parts of one plan). But I don't need legions of the damned, so it would be best to keep this to myself...