Cat Abscess...now what?

This is a bit long, sorry. I'm hoping someone else has been through this. Last Tuesday I brought my dad's cat into the vet because he had an abscess on his side. It burst just as we took him out of the carrier at the vet's. They opened it, drained it, tubed it, and then closed it up. When I picked him up no one really went over post-care instructions with me...I was just told to give him his antibiotics and to start at the top of the wound and let an iodine solution dribble over it. To the point, I did exactly what it was told. Today after giving him his antibiotics, I took his cone off of him to clean it, he licked it and it burst again. I took him back to the vet and they cleaned it up, and then told me I need to flush the solution through the wound, beside the tubing. The vet let me watch while he did it so I understand how it's done, but he was still sedated at the time. Problem now is that he's awake and not willing to put up with any of it. Two of us can't hold him down long enough to flush it out; as soon I get the syringe behind the tube, never mind into the wound, he screams murder and is all claws. I'm at my wits end. The vet won't give him a pain medication, we can't wrap him up in a towel because the wound is on his side and we certainly can't afford another $344 visit to see a different vet.