I agree with dweste,
I have used both No-Rinse Shampoo and Body Bath for a couple years when in low water situations.
You feel reasonably clean after using it and I feel it is worth the cost/time.
It is easiest/quickest/less messy to have a helper swirt the shampoo on your head while you lather it up with your hands.
Mike
I'm thankful for people on the internet who do these experiments, so I don't have to.

now I can add No-Rinse shampoo to the list of alternatives. thanks to you both.