I think this largely depends on where you live. Here in the PNW this time of year it is impossible to have clean eggs right out of the nest. Even if I changed the nesting material daily, the hens are going to bring mud in with them and up on into the nest and on to the eggs. No way around it. Yes later in the year a good portion of the eggs will be that clean, but I'm just saying location and weather matter. It is not a one size fits all thing IMO.If your coop and nest is clean, your eggs will be clean and never need washing. The only reason eggs get poop on them is if the chickens bring it in on their feet (from a dirty coop) or poop while laying (rare). I've collected, eaten or sold about 400 eggs in the past couple months. They come from the nest spotless and shiny, protected with a lovely bloom, ready for the carton or to sit in a wire basket on my counter. (Unwashed chicken eggs stay good a month unrefrigerated. Washed eggs must be refrigerated immediately.) Sometimes as I carry my treasured harvest from the chicken house, the eggs are so pretty I might even give one a kiss! I've never washed any eggs yet, either before I cook them or before I sell them.
The way to achieve this is easy:
1. Never let chickens spend the night in the nest box
2. Keep fresh straw, grass hay, or other bedding in the nest.
3. Immediately remove it if a chicken does happen to poop in the nest (this is rare).
4. Have at least 3-4 nest boxes per chicken and train them to use them all, not crowd into one. Whether you have 3 chickens or 300, the traffic per box and ease of keeping them clean will be the same.
As for what I do, because eggs last longer unwashed I do not clean them until I sell them, even if it's only a few days, if you washed them right away you'd be shortening the shelf life for your customer. I have a dedicated egg only refrigerator as well.
I also sell at 2 prices, it costs $.50 more per dozen for washing. I have customers that prefer them both ways. If I have an egg that is particularly dirty I'll either use it myself or wash it for someone that wants washed.