Assuming you're on a broad to upwind sail, think about running a few wet clothes up a
line attached to the
spinnaker halyard during the daytime. Out of reach of most spray yet consistently exposed to wind. Just remember to bring it down with someone on the foredeck so your freshly (nearly) dry stuff won't get doused on deck waiting to be picked up.
Nothing short of a dryer or other heat source will give you truly dry clothes but this works well enough in the near-tropics. And a fresh water rinse before raising the halyard does make a major difference in the end (Yeah--watermaker!)
Good luck,
Mark