I have been in a quandary over when, if, or how to wash eggs ever since we started raising chickens. In the beginning it seemed natural to wash the eggs in an organic detergent using hot water, scrub with a veggie brush, rinse them well and dry them before refrigerating. I did a lot of searching around on the internet to try to find out the best method of egg handling.
It seems that the hot water causes the egg inside to expand pushing against any bad stuff trying to get in through the shell. I think that's how it works.