This brings me to one of my favorite drinks - coffee!
This is ground coffee that I get back home in Malaysia. As you can see, it is very coarse. Not all the coffee is ground so coarse. I shook my coffee container to bring up the coarsest bits to show the texture. I use it in my french press to make my morning brew.
The grounds can be saved, dried and then mixed with your paperclay to create interesting textures. One caveat. You want to make sure you dry out the grounds completely before you mix it into the paperclay to minimize "blow out" problems