Though I'm a mountain lover, I was stuck in the desert long enough to have developed strict water usage habits. When I first retired to this tiny MidWest town, after a month or so the water department came out and checked my meter because it couldn't possibly be running right or (ahem) unimpaired.
That said, I do love a long deep bath - one reason I bought a shorter garden type tub that allows me to immerse myself w/o actually using that much water. Hot as tolerable in winter, pretty cold in the summer. Since I run around outdoors wearing crocs in the summer, my feet get dirty so the dogs' outside water pan is a square one - before coming back indoors I take off the crocs and stand in the dogs' water pan to cool and rinse off my feet. Molly Maguire and Brigid don't seem to mind. They probably like the taste.
But then I live alone except for them. If you're around other people much, you really want to be more considerate. You can rub cornstarch in your hair, leave it a few minutes, and then brush it out. That's how I clean my dogs in the winter. If you run out of soap, baby wipes work great for the stinkies and you can also just add some witch hazel to the 'bird bath' water and not have to rinse.
One more thing I do for the dogs that's also advisable for people: I take a brewers yeast tablet twice a day (they only get one). Besides many other benefits, it helps reduce BO and also discourages fleas and other bugs. I probably don't get more than a couple mosquito bites a summer.