I was kind of surprised to not see something like this already laying around. I built this simple little plugin for a server that was using ChaosSpawners, the option may be later added into it, but for now, I give to you NoNoGolems. This plugin is the solution to GolemFarms, whether it be from spawners or natural farms, NoNoGolems keeps players from making easy money off of Iron Golems. Basically, it just keeps them from dropping their goods. If your using this with ChaosSkulls, don't worry, Golems will still drop their heads, just not the iron. Enjoy.
**All my plugins require Java 8**