My groomer recommends witch hazel? and a cotton pad (like the kind you use to remove makeup) You should only use cotton swabs on the outside of the ear (the part you can see) and never put it down their ear canal. I've seen her get some nasty stuff out with just the cotton pad so I would go with that. They make special ear cleaners but they are mostly chemicals. I can't stand the smell of witch hazel so I let the groomer do it