I did a search on bathing, & didn't get much.  Maybe it's not important to all the guys here, 'cause guys think sweating is cool.
We women think differently, so here's a little clue I picked up (from TMEN, I think).  Granted, if you're short on drinking water, bathing is not an option.  But sometimes you're somewhere where there's sufficient water, but not suitable for bathing.
Heat up a quart of water to a comfortable temperature, & add 1 tbsp. of baking soda.  Wash all over with a washcloth.
That's it.  No soap, no rinsing.  And it really cuts that greasy sweat, & leaves you smelling fresh.
But you do have to wash out the birdbath  when you're finished -- sorry, it's not perfect.     <img src="images/graemlins/grin.gif" alt="" />