You will not need a lot in the back country. Deodorant doesn't work when you
are nasty, and you won't get showers - so shampoo isn't needed. Shaving can
be done at the end of the trail. So what is left? Well, brushing your teeth,
washing your hands and face, going to the bathroom, etc. Carry what you
need, leave what you don't. Check out this
article I wrote.