Would you be willing to try one more thing to debride that wound? It's very important to try to remove that scab. It requires work and it may seem cruel, but any chance of healing this wound requires it.
This technique I have tried with good results. Take Dawn concentrated dish detergent, and yes, it must be Dawn because it has a special surfactant that reacts with water to make water "wetter", and dowse the scab with the liquid right out of the bottle. Cover the scab generously with the Dawn. Then have a bowl of hot water ready. After the scab has been softened for about five minutes by the Dawn, place a wet rag soaked in the hot water over the scab without trying to rinse or wipe off the Dawn. Re-wet the rag every couple minutes and keep holding on the scab for a total of ten minutes.
You should find the scab has turned to jelly and will peel off. Any part that is stubborn and hard, reapply the Dawn and repeat the hot water compresses until those soften and can be peeled off.
We need to see what the condition is of the tissue under that scab. What is happening is bacteria is living protected under the scab and multiplying and destroying the tissue. Eventually, the infection will get into the blood stream and go systemic unless halted at the epidermal layer. If it's gotten below that outer layer, it would be extremely difficult to treat. But we still need to assess that.
This technique I have tried with good results. Take Dawn concentrated dish detergent, and yes, it must be Dawn because it has a special surfactant that reacts with water to make water "wetter", and dowse the scab with the liquid right out of the bottle. Cover the scab generously with the Dawn. Then have a bowl of hot water ready. After the scab has been softened for about five minutes by the Dawn, place a wet rag soaked in the hot water over the scab without trying to rinse or wipe off the Dawn. Re-wet the rag every couple minutes and keep holding on the scab for a total of ten minutes.
You should find the scab has turned to jelly and will peel off. Any part that is stubborn and hard, reapply the Dawn and repeat the hot water compresses until those soften and can be peeled off.
We need to see what the condition is of the tissue under that scab. What is happening is bacteria is living protected under the scab and multiplying and destroying the tissue. Eventually, the infection will get into the blood stream and go systemic unless halted at the epidermal layer. If it's gotten below that outer layer, it would be extremely difficult to treat. But we still need to assess that.