Remember the product sold in drugstores called "NewSkin?" It was supposed to be an instant substitute for a genuine band-aid. It resembled super-glue, but without the risky side-effects. Perhaps it would work the same way.
      I use super-glue and a small patch of either Kleenex or toilet paper when I need to repair a split fingernail on my "picking" hand. Gordon Bok does the same, but he uses a very fine silk instead of the toilet paper. Different social class! I believe it was Gordon who told me that fishermen in Maine soak their hands in brine to toughen them up for hauling lines and nets. Probably seeking the same effect as the saltwater callous treatment.
      Sandy