Gem cleaning does not function as explained in the guide.

I put down a cauldron, filled it with water, and right-clicked a dirty emerald on it. Nothing happens. Also tried various combinations of offhanding the gem, putting a heat source under the cauldron, throwing the gem into the cauldron, etc. Could not get the gem to clean using any method.

Issue was replicated in an install with only SkyResources in it using a DirtyEmerald.