Grubby chicks -- do I need to clean them up?

I have 6 sweet little white Wyandotte bantams who are 5 days old. They're so cute and yellow, but they are still kind of grubby from hatching and shipping. One of them even has a tiny piece of eggshell stuck on its wing (which I actually find kind of endearing). Other than cleaning up their pasty bottoms, I haven't wanted to risk them getting chilled or traumatized by bathing them at such a tender age. Before they go in the big brooder with the others, though, I wonder if I should clean them up so they don't offer so many pecking "targets" for the older chicks. How do you clean up little ones? Or will they eventually take care of the problem on their own once they figure out how to groom themselves? It's only my little yellow chickies who seem to have this problem.