There isn't a home remedy for everything, if he hasn't been to the vet in 3 months there isn't anything we can do, we cannot drive your dog to the vet or make the appointment for you. You don't even have to take the dog in, call them, send them an email with photos. If cost is the issue, TELL them that, most vets have cost plans or they'll know another vet that does. This is something that should be seen, if you're cleaning it twice a day for 3 months and its not resolved, its time for a vet visit. Was one scheduled earlier this month when you made the post? It'll likely get busy over this next weekend, make the appointment now or the wait will get longer. Ear infections and ear issues can cause deafness, please at least call your vet to see if they'd advise a visitAny other recommendations?!