I want to feed the eggshells back to my chickens. I have usually just let them dry out then I crumble them up and throw them out to the chickens. I've never worried about taking off the little membrane and rinsing them when I do hard-boiled eggs. I do rinse them if I'm just cooking the eggs some other way. Do you have to remove the membrane and rents etc. or can you just let them dry out and toss them out there?