Given the scenario, I don't think soap would be the most important thing by a long shot. Very nice to have, and somewhat important for health and morale in the short term. But probably more essential as a trade good. An ounce of perfumed soap for ... you name it.

It's not like the crew at the office are going to whisper. What office? A daily shower is a luxury. A bi-weekly scrub-down is a necessity.

From what I've read, the NASA/International Space Station folks who spend months in space (albeit with some pretty awesome non-water-washing kit) are mostly dying for a good exfoliation when they get back.

Like a scrub down with sand and hot water. Or scrub down with wood ash and hot water. Boil evergreen needles or any aromatic solvent-producing plant in hot water. Boil/rinse your dishes in hot water.

Make vinegar out of those mealy apples and use for preserving and washing. Vinegar is great for peeling oils off surfaces.

And what about a steaming hot sauna, and a good roll in the snow after? Very refreshing. Alone or otherwise.