When I fly its almost always more than one or two flights. My Saitos do make a bit of a mess. add a little dirt and its a big mess.

Now , when your car is dirty you use -hot soapy water
when your dishes are dirty you use - hot soapy water
your clothes ?
your floors?
My airplanes get hot soapy water.- carefully of course, so it doesn't get lots into electronics or engine. I use a washcloth and go over it wet then rinse it out and ring it out well then go over it dry.