Suppose a 3rd party is involved in the exchange? photog1 send his print to Jeremy, photog2 sends his print to Jeremy, when both prints are in Jeremy forwards them on. If one does not send a print Jeremy can send it back to the original photographer or keep it on hand for a new swap arrangement. Drawbacks are more expense with shipping and more work for Jeremy, but Jeremy might consider the extra work acceptable since he gets to see many prints..
I've got no problem doing it this way as long as the shipping charges are covered by those involved.
Let's see what I've got in the magic trash can for Mateo!