Brake Fluid into Grey Powder?

Why does brake fluid change into powder and granules when you leave it in your master and clutch slave for several years? How do you prevent it from gumming up the works if you intend to park your baby for a couple of years? Do you have to leave the hydraulics dry and open? What happens to the rubber when you leave the hydraulic fluid out for several years?

Actually it more than gums up the works, it also results in damage to the walls of the master cylinder. My Clutch Master Cylinder is severly pitted, to the point that a clutch master rebuild kit won't cut it. It just looses pressure around the pits in the master cylinder walls. I can't "pump it up".

Next thing is that the slave has pitted as well. This means that there is a chemical change in the hydralic fluid that results in the formation of "acid". I knew it was going to be drug related, first powder and then acid, or maybe first acid and then powder? Can't someone out there in the WORLD straighten me out here?

Maybe synthetic brake fluid? DOT5? Do I need a synethic brake fluid fix? I seem to need to replace both the master and the clutch slave. I'll just have to "eat a pickel instead of riding my motorcicle", to quote Arlo Guthrie.