Wow, I've been putting all of these things down at disposal. All I have to do is just put them in the, what is that thing that I have, a little blender, the big blender? Magic bullet, and grind it up in no time. You're gonna have plenty of powder. We've been throwing bananas and cores and stuff like that in the backyard, and it gets eaten up by the lawn people. But I never thought about this. Eggshells and coffee grounds. Got plenty of those around.