My 6 weeks old kitten has little black specs on body?

sounds like fleas. what you're combing off is flea poop (digested blood). go ahead and bathe it. warm water and mild soap won't hurt a thing. just be sure to dry it as best you can and keep it in a warm place until it's completely dry. once your kitty gets to nine weeks (or five pounds in weight) it will be old enough to put some Advantage on. until then just keep combing and bathing occasionally.