Tom,
Have you ever seen the process used to mushroom a sparkling wine cork?
I'm thinking one of the issues I have had with them is thatI make so
few bottles the corks sit around too long and are just too dry. They
never fully re-expand. I'll try hydrating them like you say. I'm
wondering if there is another step where once the cork is partially
inserted they give it a 'tamp' to mushroom it before applying the wire
hood.

Joe