Neat idea John, and I'll keep that in mind the next time I have this issue. I think I have a bunch of these in a drawer that probably need the treatment.
I once stored a pile of them in a cigar box figured how could they get hurt. When I returned some months later I opened the box intending to reinstall them and half had warped just under the pressure of laying on top of one another. I tried making the plugs to fill the center and they would not go back to the original shape in a month. Perhaps if you left them long enough? So before buying new ones thought I would try boiling water and it worked. j