I agree, Poka-bee! The commercial eggs come from chicken H*ll!! I live in a county that seems to be the commercial chicken capital of the world! The smell in the spring and summer, as you drive by, makes you gag and gasp for air!
That site was very, very interesting! I read a book once that described preparing eggs for an ocean voyage where they coated the eggs in vaseline! This stored the eggs for 3-4 months without refrigeration. But nothing I've read tops the lengths of time described in that link! I have found if the eggs are gathered in a timely fashion, no matter what material I use for nest boxes, I rarely have fecal matter on the shells. My hens just don't seem to poop in the nests....don't know why.