I keep a shoebox size plastic storage container in the small section of the kitchen sink, and use it to hold water from washing dishes, washing hands, etc., and use that water for flushing the toilet (with the water pump shut off). I'll give the pedal a quick push (pump back on) afterwards to give the bowl a clean rinse. Then, I give the bowl a spray of my sanitizing concoction (about a quart of water, a tablespoon or so of Clorox bleach, and about 1/4 tsp of Dawn dish detergent, in an old Formula 409 bottle.) which keeps the bowl clean and deodorized.
To minimize bath water usage, unless I'm really grungy, I use another storage container filled with about a gallon of hot water. I add one or two TBS of baby wash (Walmart brand is reasonably priced), and use that to take a sponge bath. Since the baby wash is so gentle, there's no need to rinse afterwards. When I take a "real" shower, it's Navy. And once in a while, if I didn't do anything to get dirty or work up a sweat, I'll just go without.
When washing dishes, I use about a pint of hot water in the largest dirty pan or bowl, and wash the others from that. All that water gets dumped in the sink mounted storage bin for toilet use, too. Dishes are rinsed under a slowly running kitchen faucet, which also drips into the shoebox.
Heck, one time I bought a yard of sod, place it near the TT and used gray water to keep it nice and green.
2011 Dodge Ram 1500 HEMI Quad Cab
2011 Jay Flight 26BH