The messages about "un-bending" chitons and percs reminded me of something.
Has anyone tried glycerine on shells?
 
Many years ago, I used to cut fall leaves (or houseplant leaves, like
croton), and leave them standing in glycerine for several days so they would
take it up through their stems.  They would retain their color and remain
pliable as well, to use in dried flower arrangements.
 
Since shells are so absorbent, has anyone ever tried soaking them in
glycerine?   They would have to be clean and free of any other oils, I would
assume.
 
Sylvia Edwards
Huntsville, AL