To clean eggs if heavily soiled I recommend using a fine sand paper and gently rub off the excess dirt. PLEASE clean your hatching eggs carefully not excessivly shaking as this will lead to early deaths in the shell. If you wish to wash eggs please ensure the water you wash them in is slightly warmer than the fertile egg NOT HOT/BOILING Water. If the hatching egg is imersed in warmer water than the fertile egg temp it will close the pores and no bacteria will get into the hatching egg. If the water is colder than the egg you want to incubate it will draw the surface bacteria through the pores and will more than likley lead to poor hatches. I also recommend adding our incubator / egg disinfectant at a rate of 1-200 which will kill off most bacteria on the eggs and allow for much better hatching results.