Save yourself the worry and just put it in the dishwasher. That shouldn't hurt the stuff either.
Or just leave the ammo in your your jeans pockets for a trip through the washer.
As to the original topic, I'm firmly in the camp that says no reasonable amount of tumbling in a vibratory or rotary polisher is going to hurt the powder.
Proud member of the NRA and Texas State Rifle Association. Registered and active voter.