My wife (and everyone else I do multi-day trips with) love hot face cloths
in the morning. If you can, keep them a secret, then on the first morning, dunk in hot water and hand to folks as they come down for coffee in the morning. Get a few dozen and you'll be the hero of the trip (at least until after coffee!). On longer trips, bring some laundry soap and use a little bleach from the kitchen box for layover day laundry. A throw bag works as a clothesline. When they're dry, roll them up
and store in a big ziploc.
Awhile back I picked up a bunch at Costco that were really plush - no one complained about tripcosting them. Look for them when you're shopping for the trip. If you get colored ones, make sure they're color fast before you use them or it can be a little clownish.