IIRC I got that idea off a Yahoo group thread; there was a lot of chatter on the subject for a time. Apparently that got back to PacBrake, as they issued a statement that the brake should be left w/a vertical butterfly axle (i.e. don't rotate it), and they came out w/their own lube product with instructions for annual lubrication. I don't think rotating it will adversely affect operation as it was becoming common practice w/good reports form users. However there isn't any better practice than good lubrication for stuff that rusts.
Baja-tested '08 2-slide 36'
Alpine: The Ultimate DIY'er Project