You know I had never thought of this, but I'm going to try it out myself with my own tincture, not as a wound thing, but as a topical analgesic. Wow, what a great question. Thanks!
I was under the impression that cannabis based topical tinctures and creams were becoming a norm for wound control and healing process.
Oh, while I'm thinking about it I once had maggot therapy.
Felt amazing, believe it or not.
I know I know, the whole idea of having 50 or so living things in your body eating tissue, knowing that for your whole life they've done nothing but eat rotting corpses.
But the little guys felt good almost, kinda like when you rube the outside of a bad cut to stimulate blood flow, but actually in the wound.
Plus I was told they secrete antibiotic saliva an such while eating diseased and dead tissues.
Totally off topic but somewhat relevant to OP's relatives non healing wound.