I and my husband used it straight into our ears. A drop or two into each ear, when they are itchy when you catch a cold or something like that. We did experience burning feeling for a few seconds but this procedure really helpes.
As for your dog, I am not really sure, perhaps a solution like 70% Clarkia -30% water, or 50-50 would be O'K, or you may even try it straight as it is.