This sounds very old fashioned type of treatment to me from what I have read recently about such things.
I am sorry to hear about the sad loss of your husband.
The science of wound care has advanced significantly over the past ten years. The old thought of “let the air get at it” is now known in most medical circles to be harmful to healing. Wounds and ulcers heal faster, with a lower risk of infection, if they are kept covered and moist.
Depending where you are you might need to get some specialist medical advice regarding the treatment that your husband had in the Hospital. It does seem to be a procedure that you need to question. Get help from a specialist medical negligence Solicitor if needs be.