The campho-phenique is likely toxic to the mites. The Honey is probably just drowning them mechanically by plugging up their little spiracles (entomologistese for windpipes). Either would probably work well.
Some people have had success just using olive oil. I think both of the above techniques would be more effective than oil alone. The honey would have the added benefit of killing any topical infections in the ear canal which had resulted from the little biters.
Patrick
Don't use herbs or combine herbs with medications or use them during lactation or pregnancy without talking with your healthcare provider.