I put the shells into a cottage cheese tub on the counter. I don't rinse them or anything - I figure any egg left in is just more protein. When it gets full I put them in the toaster oven. For frugality, I usually wait until it's hot from a mini-pizza or something and put in, or I just set the thing to one cycle of "toast."
I put the toasted shells into a plastic peanut butter jar I keep on the counter. I have a rock in it. I kinda crunch them as they go in, or not, and then shake the jar to bust the shells smaller.
For presentation to the hens I usually mix them into goopy food like oatmeal or mashed potatoes. That keeps them from eating around the shells as much.