I'd go with the Schallers.
I filled in for Stu Hamm's tech when he was was injured just before showtime (I was only backstage because the company I worked for was giving away a guitar during a Joe Satriani concert) and I was amazed to find that the hardware on his basses looked brand new.
Later, he told me that the secret was to wipe any exposed metal with 91% rubbing alcohol to remove any oils or contaminants, then spray it with Pledge. He wouldn't even allow skin contact with new tuners, only handling them with a cloth when he opened the package.
Yeah, I know. Sounds weird, using plain old Pledge (not lemon Pledge) when there are so many high-tech creams, wipes and sprays available, but it works dandy-o. I've been doing it ever since, and all metal parts on my instruments gleam.
Gold hardware is the most resistant to corrosion, but it can still happen because of infiltration of sulfurous compounds (most often emitted by a drummer, no doubt) through pores in the gold plating. Apparently Pledge seals it up just fine.