I agree with Jade, if the wound is absessed it will need antibiotics to clear up the infection so it doesn't become systemic. After such a long time I would really be concerned for her about this....and hope you can find away to take her in for some help..antibiotics are very inexpensive, phone around and find out where theres a clinic that you could get a Vet to prescribe this without charging you alot for the exam..
are there humane societies in your area? sometimes they have access to help as well..
Perhaps a phone call would even find a Vet who would prescribe this without the cost of an exam, I don't really condone this unless other ways fail and finances are extremely tight....just an option.
If its still superficial and NOT hot and oozing than I can tell you of a method that is used successfully for a poultice for wounds. Its called SLIPPERY ELM BARK...its only avail thru a health food store or somewhere that sell high quality supplements...or online
Its a powder and you'd mix it into a poultice and apply to the wound.
It can also be used internally for many tummy or intestinal upsets BUT there are only a few brands that are safe for CATS for internal use and since she would lick at it I do recommend you find the proper brands, I will list them for you and also give you an online source that I have used MANY times...
SLIPPERY ELM BARK
-Frontier...found in bulk organic
-Mountain Rose Herbs- Slippery elm bark powder
-Natures Sunshine
-NOW Foods...
the one I use is from NOW Foods and this is where I buy it from.
http://www.iherb.com/Now-Foods-Slippery-Elm-Powder-4-oz-113-g/788?at=0
good luck, please post with updates...♥
I have used different things on my cats. One of my cats wasn't stitched up enough and has a huge chunk of skin that drags along with being obese. She's got arthritis in her back legs so alot of activity isn't working out for her but she's on a restricted diet. Well she can't groom well around the fat and extra skin so her butt winds up sore and inflammed. I didn't know it until I found her trying odd positions to wash it. I can't afford the vet either so I called and just asked advice. The vet I called said to try with a warm cloth to wash the sores, and you can put a little vaseline or antibacterial cream on them. I did that and it's healing nicely.
If it's looking gross, it may already be abscessed and probably is since it's been over a month in which case kitty would need the vet, the area cleaned out, then antibiotics. And cats will not show pain unless they are severely hurting so just observation alone isn't really a good barometer as to the level of pain for a kitty. Please find a way to take this girl to the vet since she may be suffering. It's so hard to tell with an animal so best to be on the safe side. Maybe the vet will allow pymts...there is also something called Care Credit where you put the fees on a credit card so the vet is paid, then you pay the card. There are a number of suggestions at the top of this forum on financial help. Give it a look and best of luck!