When the paper clay dries, it is very hard (and heavy!) and though it's possible to sand, it's not the easiest to do so, and I didn't want to create a dust storm with a Dremel. So I figured I could create a smoother texture by applying a layer of Monster Mud to it. The first layer did do just that, but a second one refined it some more. I'm still debating whether to apply a third one (all of them are relatively thin), but I'm thinking I'll sand it down lightly after the second layer dries and see how that looks (so much for not creating a lot of dust). I'm guessing it will be sufficient, though. I also figure it provides a layer of protection to the paper clay underneath, though it will eventually receive a waterproofing coat at the end.
Here are some progress update pictures.
Fully covered in paper clay
With one coat of Monster Mud
And after a second coat
I didn't worry so much about the neck since a lot of it will hidden in the folds of his clothes, and a "turkey neck" looks appropriate on an old geezer who's spent a lifetime digging graves. After he's sanded (hopefully) smooth, I'll work on the eyes and ears.