For commuters, it's a real issue. If you work in an office, you can't show up at work with filthy hands.

Auto parts stores usually stock several brands of waterless hand cleaners, and they're a lot stronger than baby wipes or Purell. I have a small container of Castrol hand cleaner in my under-seat bag. It works fine. It will clean up the nastiest grease and grime. It's a bit abrasive, if that's a concern, but there are probably other brands that are non-abrasive.