My gorgonian has some flesh on it, but has a bony skeleton under the "skin". What I was told by the LFS that I got mine from was to cut it, place it in the sandbed for a couple days till the "skin" died off. Then glue that bony skeleton to a rock. Otherwise the "skin" is whats glued and once it dies off it will become detached.
I have fragged mine several times now using this method and it has never failed me.