How to ship a full suspension bike frame without the shock?
Besides all the other protection measures of wrapping and padding the bike's tubes, you can make a "fake shock" of wood. That is, measure the distance between the shock's eyelets, cut/saw a wooden "stick" from a board so that it fits inside the frame, drill two holes on its ends, and mount that stick instead of the shock. The same trick is used to place wooden blocks in frame's/fork's dropouts when the frame is transported without wheels so side side loads do not bend them.

The wood is an excellent material for the task, as it is firm and is easy to work on with almost any type of saw even by a person with little experience. Size tolerances can also be very wide — it won't make a difference if your fake shock is 5mm shorter/longer and ugly as hell.