How about suggesting this to Mythbusters?
I have been loading up a boatload of new LC 09 brass I have been buying. Good stuff but tarnished. I hate tumbling un primed brass so I have been loading them and then tumbling. Using TAC powder and I have had no problems with them. I have also tumbled other tarnished ammo with zero problems. I don't like crappy looking brass.
As far as being unsafe I tend to think that is some more of the internet commando stuff. Kinda like a 5.56 round with missing powder sticking a round in the barrel from the primer ignition.
All my reloads go in the tumbler with walnut for about 30 minutes,no problems.