I would also give them each a tablespoon of good quality dry cat kibble every other day for a couple of weeks - again, to try to give them nutrients that would help them heal (protein, vitamin D)
I would not bandage the feet, but I would be sure to put ointment on them at least at bedtime.
I am wondering if they could benefit from some flaxseed meal in their food - I seem to recall there is something in flax that is good for the skin and bill.
Anything going on with the weather, or...