"One" command block command: http://pastebin.com/zTrVSLRn
You can safely remove the last 3 commandblocks which were used to make the stone cauldron only.
Minecraft 1.8.6 broke the dispenser randomizer which is used by many Minecraft maps. A few months ago I experimented with another concept for randomizers which I call the Squid cauldron. It supports up to 360 outputs at a speed of 20 outsputs/sec. Hope you guys can put it to good use!