That's pretty severe. She may recover from this with care, chickens can be resilient.
Personally, I'd still cull her do the severity and damage she's suffered. I don't say it often nor lightly.
I've never used vinegar on wounds so couldn't say how effective it would be. Soap/water...
Sorry about your hen.
If she's a meat bird, then it may be kindest to put her down.
Otherwise, flush the wounds, you can use warm soapy water (dawn), get all the maggots out of the wound, pick them out by hand if necessary.
Do not use Peroxide anymore, one time is o.k. but further use can...