I think for now at least you have to keep her vagina lubricated past the point where the tissue damage is.This is the plan. Tomorrow I'm going to close off the brooder, cut and screw a piece of plywood over HC between the coop and the brooder and drape an old, heavy sleeping bag over the top and front and hope that will make it dark enough. I'll check using the brooder cam.
I'll go out before I get ready in the morning for work and get them off the roost with the run flood light so she has about an hour to eat her fill then put her in the dark brooder before I leave for work Tuesday through Thursday. I'll ask Nan to go into the coop and open the brooder sliding door and let her out when she gets here at noon so she can go out and eat and drink. That will give her about 6 hours of light to eat. I hope that's enough to suppress ovulation but also make sure she has enough to eat and drink for the day.
I think I am right in saying that the glands that normally supply lubricant to the egg are above the exit from the intestines at the base of the uterus where the shell is formed. This would mean lubrication quite a long way into the vagina so the egg is very well coated before it reaches the places in the vagina where there is scar tissue forming.
You may be able to discourage egg laying for a while by keeping her in the dark but I can't see it as being a long term solution, certainly not long enough for the damaged tissue to heal and the removal of the rest of the necrotic tissue.
Metacam will help in the short term with the inflamation and the pain, but it's quite powerful stuff and not something to be used for long periods of time.
I think you may have to resign yourself to puncturing each new egg as it appears and carrying out the procedure you've just done until everything is clean and healed.