It actually happens fairly often on couchsurfing. Couple A from New York wants to spend July in San Francisco and swaps with Couple B from San Francisco who wants to spend July in New York. I've seen it happen with entire families too.
Less likely to work internationally, but domestically, it happens. It's the key exchange that's the hard part, but the safest is to leave the key with a neighbour and then call them from the other side to give them the okay.
Less likely to work internationally, but domestically, it happens. It's the key exchange that's the hard part, but the safest is to leave the key with a neighbour and then call them from the other side to give them the okay.