Last spring I sent out a large number of cuttings that were totally covered in damp...not wet...coconut coir, and placed in a large zip-lock bag. They sell these super-sized, zip-lock bags at the market. They are large enough to hold sweaters, etc. I try to take straight sections of branches. I then roll the bag containing the cuttings, and place it in the shipping box that's packed with dry newspaper. The cuttings are always surrounded with, and cushioned by, the damp coir, and they'll arrive in great condition. The receiver can either plant the cuttings, or, store them in a cool place, right in the original zip-lock bags. I buy the dried, compressed, coconut coir at the local pet supply. It also makes a great rooting medium for cuttings.
Frank