There is a post on here that a guy done an experiment 25 uncleaned vs. 25 cleaned with a qt of warm water (warmer than the egg) mixed with a tbsp of betadine and a soft baby hair brush. They had they same hatch rate. Another lady commented on his forum that she has always washed her eggs with just plain water and her hands and always had an excellent hatch rate. Me personally I would wash them if they were really dirty, but a lot of people wouldn't wash them or just wouldn't use them. Good luck!