I haven't been cleaning it. When I'm ready for a new batch, I just melt it in the oven around 120-150F for a few minutes, and introduce new chocolate.
I think the drum without the cover is safe up to temperatures of 165. Ovens vary widely, so I put the probe in the oven to make sure it's safe. Typically, I'll pre-heat the oven, and when the probe hits 150, I put the conche in with a couple more short bits of heating.