I use olive oil in my own ears. I have narrow ear canals, and they have a bend in them (!), and often my ear aches a bit in the morning after lying on the pillow. I have had them syringed once. I put a drop of olive oil in and it softens any wax, which works it’s way to the outside naturally, and will also bring any dirt with it. Also wonderfully soothing. Never tried it with a dog, but can't see it would hurt. Milo also had narrow ear canals and spent a fortune on ear troubles. Olive oil has been used for centuries, honey too (not for ears though!).
Lesley and Dylan