Hey bud! So obviously, keep up a good dialogue with your veterinarian, and trust his advice, as he's the most qualified to give it. Seeing your little buddy frequently and examining his ears, your vet can give you better advice than we probably can.

With that said, you're on the right track with a few things. First of all, moisture is definitely the enemy, so good call. What do you wash the ears with? I know back when I worked as a tech, we would often use isopropyl and some cotton to get in those ears real good and dig out the gunk, then the isopropyl evaporates out real quick so moisture isn't much of a problem. I don't recall any of my medicine lectures saying not to use alcohol, but talk to your vet about it. Also, keep in mind that Basset Hounds' and Beagles' ears are naturally real tough to keep dry and clean, so you've got your work cut out for you.

Second thing, resistance can certainly be an issue, though I'm not sure that's a really common problem. Some of the veterinarians here can tell you better than I could.

Do you recall what diagnostics your veterinarian's done? Usually we want to swab the ears, and swipe the gunk onto a slide to see if we can actually see the organisms under a microscope. I imagine your doc already did that. With something that doesn't seem to be going away though, I'd be looking into more advanced diagnostics. You'll pay more, but it might be worth asking your vet about that. Personally, as a student imagining what to do without worrying about your budget, I'd like to send off some samples for a culture and sensitivity. This'll tell us exactly what organisms we've got living in there, and what specific antimicrobials those buggers are sensitive to.

You may also want to talk about addressing the inflammation with your vet. It sounds as though you haven't got any medication on board for that, and it may be possible that the inflammation is making it harder for your animal to fight this ear disease. Just be careful with that, since many anti-inflammatories can themselves be immunosuppressive.

Lastly, no matter what, do not give your animal any medications unless the vet says so. Dogs handle drugs differently than we do, and even simple OTC drugs that we might use for ourselves can cause terrible illness in them. I hope this wall of text gives you some ideas of things to discuss with your doc. Good luck and keep us informed!