This certainly is a tough spot that you're in. How frustrating it must be for you!
I can totally understand your concern with not wanting to anesthetize your pig. Pigs aren't particularly easy to work with, and there are other factors concerning anesthesia in pigs that can also make things tougher. They're not like anesthetizing a dog...
As far as trying a different antibiotic, as I had explained previously, if there is still a foreign body within the ear an antibiotic will do no good whatsoever, unfortunately. Yet the problem is, there is no sure way to tell if there is something in there, or the condition of the eardrum without being able to view all the way into the canal.
So................one way to calm down a pig, and perhaps to the point where you may be able to get a look and perhaps get some of the ear canal minorly cleaned, is to literally break out the beer. I often use beer often as a mild sedative, and I haven't yet met a pig that doesn't love it (for some reason they seem to prefer Pabst Blue Ribbon...). If she weighs 250#, she could safely have 3-4 12 oz. beers. Just pour them into a bowl and let her drink. Wait about ten minutes and give it a try. Do NOT use anything like Q-tips, as they could cause things to become compacted. Instill a small amount of sterile saline or ear flush (that does not contain medication) into the canal, and massage gently at the base of the ear. Use some cotton to remove any debris. This can be repeated several times until things look cleaner. It will still be a stroke of luck if you're able to see very far in, but it won't hurt to try. If you're fortunate enough to see something that shouldn't be there......gently try to remove it with some tweezers.
As far as trying a different antibiotic, LA 200 (Oxytetracycline) is available over the counter without a prescription. An effective dose for her would be 4cc (800 milligrams) given in the muscle once daily for 5-7 days, and could be effective if there aren't the other circumstances present that we've covered. I'd also recommend using an 18 gauge, 1" needle for injection. Always use a new needle after you have drawn the medication into the syringe. A new needle is less painful, and also more sterile. There is no need to clean the area where you will be giving the injection. If there is no improvement within 3-4 days, then you will know if the problem is more than just an infection. Be sure to not miss any doses, and also give for at least 5 days in a row.
So again, without getting her seen by someone who knows pigs, this is the best that I can offer you. If she does get sedate enough from the beer, do you think it would be possible to (with some help) get her into a truck/crate and get her to a facility?
So please let me know what you think, and hopefully we can get some progress going! And also, please let me know if you have any further questions.
Best of luck!