I routinely tumble/vibrate loaded ammo to remove the case lube. I use pitch free saw dust (make it myself with chain saw and dry piece of wood, last a long time). 15 - 20 minutes cleans the case off nicely.
As to breaking down the powder; many have cryed the sky is falling as to the "dangers" of this. However, if you have any experience on track vehicles in the military you know what vibration is. Ammuntion is routinely carried in all sorts of manner on those vehicles for days, weeks and months at a time. If the vibration was going to "break down" the powder the military would know about it. There isn't a problem. Many reloaders have also conducted tests concerting powder break down by tumbling/vibrating loaded ammo for hours and then chronographing the ammo before and after. There was no indication of powder break down or pressure spiking.
I have an Oehler M43 PBL which tests pressure and allows me to "see" (via the time pressure curve) any spikes or abnormalities in pressure. I have tumbled and vibrated (I have both machines) 7.62 NATO ammuntion (US M118SB and M852) with both ball and extruded powder for 48 hours. It was very clean and shiney BTW! I pulled 5 bullets of each load and compared the powder under magnification with that of powder from non tumble/vibrated rounds. There was no discernable "breakdown". I then fired 10 round strings of "before" and "after" In my test bolt action .308W using the M43 to measure pressure and velocity. There was no discernable difference in either the pressure or the velocity.
Like I said I routinely tumble/vibrate loaded ammuntion to remove the lube. However, I mostly prefer to inspect rifle cases such as 5.56, 7.62, 30-06 and 8x57 cases and clean the primer pocket prior to loading. So I will FL size, clean the lube off by tumble/vibrating in the saw dust, inspect and then load them on my 550B. I use a NC die in station one to give consitency in press operation and to iron out any dings that may have occured between FL sizing and loading. That works better for me and I have a higher confidence in the quality of the ammo that way as I've inspected the case, cleaned the primer pocket and know there isn't any debri in the case or flash hole. Just the technique I use for better quality ammo.
Larry Gibson