Its funny that Myth Busters has proven that a ball actually moves slower off a corked bat than it does a regular one.
I guess it always comes down to perception though. If my bat is corked, it must mean I'll hit the ball better.
Well, a corked bat is lighter, and for an aging hitter, picking up a little swing speed might be just what is needed to keep the average up. Rose wasn't hitting for power anyway at this point in his career.