Time will tell Hawk.
So i built my shower and boy am I pleased with it. Through the process I tried to make it of materials that serve more than one purpose. First thing was I needed a tank to hold water. Walmart has blue water jugs that are designed to just hold water and that is all. They have a nice spout on the lid so a guy could lift it up on a surface and let gravity do its job, pouring water through its nozzle on you to soap up, then rinse. As a non powered simple solution it should work well. But thats about all it would be good for and I dont favor single use items, especially for tight quarter living.
The other idea i had was a sprayer jug. The type with a hand pump that pumps air into the jug to pressurize the water. It would make a good way to rinse, and for water conservation, high pressure low volume is a best case scenario. It also takes up very little room and doesnt weigh much when full so its portable. The long wand would however make it awkward to use, though modification shouldnt be hard. The problem with it is washing hair wouldnt be easy. A 5 gallon bucket would solve that, and the sprayer would store inside it when not in use. But then, you need to get water every time you shower and water isnt easy to get, even in the city, so when you get it, its best to tank up.
That brought me to what I decided to make. Coleman makes an amazing 50 dollar cooler that holds 70 liters of water, stainless steel hinges with a reinforced lid to act as a seat. Two bonus uses right there, its a cooler and a seat, with a measuring tape molded in and cup holders. Its nice. It also has a drain plug on it, allowing a person to set the cooler on a tailgate and bathe that way if needed, letting gravity do its thing. Of course for parking lot camping i prefere privacy. So I needed water pressure that works on 12 volts. Nothing a boat bilge pump wouldnt handle. I got a smaller one because i dont wanna use too much juice, or water. I bought a 25 foot water hose, cut 15 feet off and with the help of a heat gun, heated the 5/8 water hose cut end up to expand enough to fit the 3/4 outlet on my bilge pump. The other 15 feet, that gets used to tie into a faucet at a gas station by me to fill my cooler no need to take it out the truck. Thats convenient. Also, the pump can be rerouted into a stream to pump water from the stream into the cooler. Put a water filter inline and you have drinkable water.
I found a spray nozzle to use as a shower head. The pump makes enough pressure to use all its settings, but full and shower are the two I use the most. I picked the spray nozzle that had the most and largest opening holes so as not to over work my pump, especially since I am going with more volume and less pressure on this rig. Maybe a stronger bilge pump would do better. It takes a lot of water to get the soap out of my long hair. And of course, a hair cut is not an option. Never know when I may need some cordage and not have any
A shower uses about 1/3 the volume of the cooler, so one fill up last 3 times. And when done, it all stores inside the cooler out of the way. Not bad. Bath every other day, and use baby wipes for a good wipe down in between and you are good to go for a solid week. If you think baby wipes for a bath sounds gross, you have never tried it. It works great. Just use non scented ones, they dont leave a residue behind. When showering, the water just runs down to the bed of the truck, down the bed linner corrugations, and out under the tailgate. Its just soapy water and harms nothing. Just got to clean the truck bed floor to keep away that locker room smell.
Next issue to resolve is water heat. Cold water will make you reluctant to get all your parts, and make bathing an oxygen reducing endeavor with all that gasping. I believe I will make a solar water heater on the roof of my camper. At 4 foot wide, 12 foot long, i have room. The idea is a slow circulation on a timer. Water sits in tje hose on the roof, get hot, pump kicks on, cycles hot water into the cooler and puts cold water on the roof. It shoukd work great spring through summer. In the winter, sponge baths and gym showers are probably gonna be what happens.
Anyways, didnt mean to write a book on the subject of me bathing, but there ya have it. Im quite pleased so far.