When we are wild camping we have found the Hozelock Portashower to be fantastic! It has a 5l capacity and the pressure that you can build up in it gives a fabulous spray. Between the 2 of us we can shower using only 1 fill. We use about 1.5l each while the rest is used if I need to wash my hair. We do use this in conjunction with a litre of water in a basin to wet and soap a sponge. If water is a bit more scarce, this can obviously be cut down even more. We got ours from www.tooled-up .com for £18.59. Click on the picture to go there. Having checked through our local garden centre though before we left, there were very similar shower type bottles used for weed killing/spraying and they had smaller capacities ie 3l.
Girls, this one's for you. The Shewee is amazing. I had my reservations about using it .... but no longer. No more hovering over stinky, horrible loos as this allows you to stand and pee. Once you get the hang of using it, its pretty wicked and despite what Jeremy Clarkson says, I can attest to the fact that it works! Give it a try.
You'll find some more info about things we really like here

