I wouldn't worry about the beak just yet. Baby birds have softer beaks than adults, it may be something the bird grows into, and it should change shape some as it matures. At this age, they are just eating machines. If it is still a problem, a knowledgable groomer can help reshape it after he is fully weaned and a little older. Your best bet for cleaning is just a damp washcloth. Since he isn't fully feathered yet, make sure you use warm water so he doesn't get a chill. Make sure the room is warm and free of drafts as well. If there is dried food on him, you'll just have to work on it slowly and it may take a few tries to get it all softened up enough to come off. If you're too aggressive cleaning it, you may pull out feathers or damage the growing follicles. You don't want to give your beautiful baby bald spots that never fill in.