Clearly this has advanced into a serious situation.
The tissue has entered the stage where its actually rotting.
"Lack of circulation" folks. No oxygen to the cells.
No oxygen to the cells equals death of the cells.
I'm guessing this man barely moves his body and drinks little to no water. And probably the diet is whatever he wants including microwaved frozen foods.
The first things I would do would be to get him moving and drinking water.
This might arrest the direction that this is heading.
From there the suggestion of the mud packs would be in order to get this reversed and after that of course there is a plethora of remedies that should be undertaken.
But first should be rock bottom basics - drink water and move the body to get the circulation going. Otherwise its not going to be good.