Someone who knows about dogs, specifically er Spaniels?

If you know anything about er Spaniels, then you know that they get ear infections. It's really gross and I've taken him to the vet several times to get it fixed but nothing works. I found something on the internet that involves Boric Acid, Alcohol, Vinegar, and Iodine. Now I was fine with it until I bought the stuff. That is some really strong stuff and you have to pour the solution into his ear c and I'm a little worried about it now. I'd like to hear someones opinion about this solution.