That is just pathetic. My first thought was that they were duck eggs because some sellers send dirty waterfowl eggs, but they are CHICKEN eggs! That is ridiculous. I would be furious too. Can you imagine the filth that person's nests must be in if their chicken eggs are filthy like that? In my opinion, there is no excuse for sending dirty eggs. I deal predominately in waterfowl eggs and we won't even send dirty waterfowl eggs.
There is no excuse for it (especially chicken eggs). The birds should have clean nests to lay in and clean eggs should be sent. With waterfowl, we do have some breeds, like Runners, that notoriously do not lay in their nests. In that case, we throw out eggs that are extremely dirty and clean eggs that are cleanable. To clean the eggs, we first lightly sandpaper off what we can and then clean off the rest with warm water. I *never* send a person (even someone I am *giving* eggs to) dirty eggs. It is just so incredibly lazy to me. I send eggs that are immediately ready to go in the incubator. I would really give that seller a piece of my mind.