Have a few wet-wipes (moistened towelettes) in your bag. I love these for cleaning my hands before eating when I cannot get to water, for a quick face wash or stain removal. You can order them from minimus.biz or pick up a few for free if you happen to wander into a casino. They’re also great for cleaning a germy hotel tv remote control before you start using it.
One caveat that I learned today… do not save these wet-wipes for months on end as they dry up. I had one towelette in my bag that had thousands of air miles on it from my travels, but it had no ‘wet’ left on it.
So pick up a stash and use them regularly in your journeys. You’ll feel fresher, smell cleaner and reduce stains and germs.