I was leary at first too, but I trust the experts here on BYC. The bloom (protective coating around the egg) protects the developing embryo. As long as you never wash hatching eggs, even if their is a bit of poo on them, they will be fine.
I had two eggs in the incubator that were washed ( I marked them with a sharpie as washed eggs) and lo and behold they both were some of the first to hatch and the most active..
There is a lot of great information out there and then there is some that has been proven wrong time and again.. I believe this to be one of them.
