i have scrubed before 2 got 6 out of 7 but i didnt want to say to because most sources say not to i have heard that hatcheries put he eggs in buckets of warm water, u can do that to get the humidity up fastSince it's a bit of a debate, I would like to share my opinion. I personally would wipe them down with warm water. It won't really affect the eggs, and wiping them has proved to save them in my case. I have tried both ways. When I left them be, many of them died (not from mold, but from bacteria and lack of pores). When I cleaned them, all but one hatched. I realize there are other factors, but I also always clean my incubator eggs from the start and get 95% hatch rates. If you are questioning whether to clean them for the start, thats really deabtable and people should just do what they feel is right. But since these eggs are literally covered in other egg contents (blocking pores) I would definately clean them. Might I add, I did scrub too. You should make sure you get close to all of the yolk off. You will also want to change the nesting material, and if it's really bad, wash the hens underside and give it a quick blow dry. Just try to have the egg back underneath of her within 20 minutes.