So, a couple years ago I bought these shoes at goodwill to mix cob with (it must have been during the cold part of the year and my feet were hurting). I just pulled them out from under the yurt, and they still had mud on them:
A bit of elbow grease and a bunch of actual grease and they are ready to go. I love rescuing old stuff.
And, you can get get a lot of baking done in the earth oven while you're cleaning shoes: