I have such a time keeping my nesting boxes clean! I have to change the shavings all the time. The problem now is my one hen who isn't laying, but insists on sleeping in there, and also the fact that Kenny Rogers always hangs out in the boxes watching the hens lay their eggs. Kenny Rogers poops everywhere
I brush my eggs off and leave them at room temp. They'll stay fresh for weeks and weeks, partly because our kitchen is unheated and usually about 40 degrees.
I have 5 nesting boxes, and they use 2 of them, but they alternate days. They insist on all laying in the same box each day, sometimes at the same time. Yesterday the coop camera caught images of Loretta laying an egg while sitting on top of Irlene. You can actually see the egg fall out of her butt onto to Irlene's head! I started to post the pictures, but it's actually pretty gross. Funny, but gross.