Patrice,
This is just my 2 cents, but since burl grows in all directions it doesnt do any good to paint or just wax the ends. In your situation I would find a place where you can dunk those in wax. Then set them aside. Thats what I would do with your cherry burls. I have had a lot of cherry burl twist and crack on me, its one of the worst for that. You could look into a chemical for dealing with wet wood, and then cut your burls up into blocks and soak them. Lot of wood workers use pentacryl or anchorseal. I had a thread posted earlier about some box elder burl that I used pentacryl on, and the color is almost back to the original today and its only been 2 days. Mine was crumbling and soft on the bottom and those were the ones I used it on. I would do a little research into it.
Larry