While we are on the subject of cleanliness, you should know that Sea to Summit make an excellent ultralight camp shower. They have reduced its weight over the years so that it now weighs a mere 120 grams. I suspect that this weight inclues the bag so you might subtract perhaps ten grams from that. I know this was the case with my older model.
For that weight you get a 10 litre shower which will give you about 7-8 minuetes of shower time, plus the rope/suspension system. As you can easily turn it on and off with the shower rose this gives you plenty of time. Simply wet yourself down, then turn it off, lather up, rinse. Do the same with your hair. I find I have no trouble getting sparkling clean long before the water runs out.
Thing is you need to heat about 5 litres of boilng water. An ‘ideal’ temp I find is about 50:50 boiling to cold water. (Put the cold water in first!) Della and I used to carry two billies of about 1.4 litres each which gave us 2.8 litres of hot – so 5.6 litres altogether. This was ample. We carry slightly smaller billies now (100 and 900) but it is enough.
They claim that the black colour will enable you to heat the water for your shower by leaving the bag in the sun. In my experience this will work on a very hot day but in the cooler months and winter when I go camping the water would become only tepid at best. As I would heat the water with a fuel stove anyway there would be no saving to me in this method.
The shower also doubles as a waterproof dry bag at other times: https://seatosummit.com/product/pocket-shower/ Approximate cost A$35 (August 2018)
If this seems like too much to carry, (which it is for me – I still use my Sea to Summit one when we are car camping – as in Scotland here), you might do what I do and shower with your 2 litre Platypus bottle. Here are my instructions how to do just that: http://www.theultralighthiker.com/bathtime-on-the-trail-the-one-gram-platypus-shower/ The advantage of this system is it only weighs 1 gram and doubles as a water bottle!
PS: Here is a great way to make hoisting your shower over a branch easier: http://www.theultralighthiker.com/?s=bush+shower
