My horse had an injury last year like this. I used vetericyn (recommended by my vet and worked so well!) while bandaging. At the point you are at now I was bandaging every second day providing the bandage lasted well. I would rinse the wound as long as there was still the slimy stuff being produced on it. Then I would pad it dry Spray the wound with vetericyn, spray non stick pad with vetericyn and then wrap with guaze roll (not too tight) then vet wrap or just the vet wrap. For a while when the wound was still a fair size I would put a standing bandage on as well. When we were okay'ed for work his wound was much smaller than your horses seems to be and I made sure the wound was bandaged and used polo's. If you want to chat about this feel free to e-mail me cjandr @ Hotmail.com (take out spaces). Vetericyn was all I used and it was awesome, my horses didn't seem to be bothered by it at all he stood ground tied with a hay bag for this process for over 2 months.