I ended up getting a stockpile of a few hundred of the new barrels, and gave up part way through smashing them all by hand. It was way too much work. I wrote this to start a barrel smashing party and iterate through every one of the dropped barrels, smashing them all. After it is done, if you got any of the "rare" barrel items it will tell you which ones you got and how many of them.
svn checkout https://github.com/geistbar/barrelSmash/trunk