This will teach me not to go to work when the eggs are hatching in the incubator

The last (I'm assuming) chick to hatch in the incubator was very dry as the humidity levels had gone right down, and it has dried on 'gunk' on it. Can I wash it? I've left it in the incubator with humidity levels up (Other chicks have all sucessfully been transferred to broody hen)
I was going to wash it and pop it back in the incubator, then sneak it under mum when it had fluffed up?
Any thoughts?