His ears could just be caked with dust and greasy stuff. One thing you could try is take a little bit of cooking oil (canola, corn oil, stay away from olive oil) put a few drops on a cotton ball and rub the ears a bit. See if you get any dirt and grime off of them. 90% of the time the ears look moisturized just from doing that because it breaks up and removes all the icky build up on the ears from dustings and everything else that the chin has come into contact with. If you do this, wipe off all the excess you can so that it doesn't end up making the chin extra greasy. After that, wait about an hour and give the chin a dust bath. That will give the oil a chance soak in and not just make the dust stick right to the ears.
I would stay away from lotion because of the ingredients. I wouldn't want the chin to eat any of it...things like lotion make me nervous.