I'm interested in finding this out, too. I've been selling eggs for two months now, so I've been trying to figure this out as well.
From what i've learned I've decided to just brush off if possible, or hot water on a papertowel if a smear, or if must be washed use a veggie brush under
hot running water. The water is supposed to be hot because cold water will cause the egg to "suck in" the water, possibly contaminating the egg. That being said, commercial
egg washers submerge the egg in water/washing powder solution, and then some spray with oil.
I was wondering if I should get one of those olive oil misters for cooking and spray with food grade mineral oil as well?
No farmers I know do this, so anyone here do it? Or not?
Also, someone brought up the fact that since I am selling them so fresh, and commercial ones can be much older by the time they make it to the public, they last just as long
anyway?