The amount of "damage" done by removing the thin layer of oxidation is so slight that it would never matter.  Long before a case would be weakened by the loss of metal from polishing, the primer pocket will work harden and become too loose to keep using the case anyway.  Clean, shiny cases wear your dies and chamber less than cases covered in various oxides of carbon and nitrogen and probably release the bullet somewhat more uniformly but whether any of that would ever approach the level of being measurable or not is questionable.  The overwhelming probability is that repeated exposure to combustion gases will erode the barrel before the effect would become significant.  But, working with clean, shiny brass is unquestionably more fun than working with brass that looks like it was dug up from a Civil War battlefield.

JACK:
   Handsome is as handsome does, hey?   I use the ultrasonic cleaner, and when dry, brush out the necks with a bronze brush.   Been 20 years since I cleaned a primer pocket, too.

CHRIS
RGChristensen

You can bypass the timer or replace it with a switch.