The cabin must have been a bit festy after 2 blokes spent a couple of months airborne in it...
They did have a shower arrangement of sorts, apparently - although one does wonder what level of shower cleanliness one could attain in the slipstream of a 172.
Maybe it was just the old "ABC" that the grunts in SVN did, out of a waterbottle! ([under]Arm, Bum & Crotch, in case you needed to ask).
The history of the record-breaking light aircraft flights around AZ, NV and CA