
We use Epi-Otic too...Have been using it for over 10 years.
Clean about once a month or when needed.
We put loads of Epi-Otic in the ear, massage for few minutes outside at the base of the ear and let the dog shake, then use cotton wool.
It is amazing how much stuff can come out of a seemingly clean ear when cleaned like this!
In the summer the dogs tend to swim a lot so get water in their ears and seem to need more cleaning.
One of our bitches also gets mucky ears when in season!