Well, I have never used drywall compound, but I have used papier mache before. And I have found that wall paper paste works best for papier mache. What you do is mix up the wall paper paste and then take strips of paper and slide it through or dip it in the paste. That way it doesn't clump into balls. Then after it is on whatever you are putting it on, you can go back over it with a paint brush with paste on it to seal it even more. And the wall paper paste is better to use than conventional methods because it won't mold.
This doesn't really answer your question, but I hope it helps anyway!!