Recycled primers ?

I'v been dropping my spent primers in with my corn-cob and a spoon or 2 of vinegar when I tumble brass , then put the brass in an ultrasonic cleaner ...
(tumble and sonic each for more than 2 hours)
Is there anything wrong in using spent primers like this ?
  
Oh-yea , everybody knows that the prettier the brass is the straighter it shoots ...

I would be more worried about the vinegar than the primers, but that's just me. I also don't like to add anything liquid to my tumbling media so it doesn't stick inside the cases.

As far as the Ultrasonic, I have never had to go more then 3-4 cycles (24-32 minutes) on brass. Maybe your Ultrasonic Cleaner has a larger capacity then mine, therefore requires more run time for all the brass?

The only problem I have heard of with using spent primers is the dust that is left in them after shooting. I have heard this is rather toxic. I guess if you wash them out well that might take care of the problem.