Suggest Treatment For Deep Open Wound In A Type 2 Diabetic Patient

My father has type ii diabetes. He currently has a wound with a diameter slightly smaller than a dime, and about 1/4 of an inch deep. He is currently taking antibiotics for a separate reason. He has had ulcers on his feet before and has used iodine in the past. He is currently thinking of using Dakin`s solution, but I told him to wait. Is there any advice you can give on any possible treatment such as packing the hole with some type of ointment, or packing the hole with gauze soaked in some solution?