It's hard to say. How much longer do they have? Also, remember that any recovery will take a week to materialize so don't make changes and then more changes without giving the plants a chance to react. Also note that the damaged leaves are what they are. They won't recover, although if you done the right thing, they should stabilize unless they are damaged to the point that the plant has decided to jettison them. You should be looking at new growth to gauge what is happening with the plant, not the older damaged leaves. Pics?