Currently on a longer vacay, was able to do laundry at a friend's near the beginning as planned, but two countries later I'm currently in a laundromat desert at a hotel near an airport.

So it's not really something you can rely on being able to do, unfortunately.

Edit: Just sink washed some things that should get me through the rest of the week after seeing that idea in the responses. Now it just rained, so fingers-crossed the clothes dry faster than they get the wet-mold smell