for myself i usually handle solid waste by either deffing in a hole dug with a garden trowel & covering it up, or if i need to be discreet, crapping on a pad made with a double layer of paper towel, then enclosing the waste & putting the entire used pad into a paper bag. In fact, i buy brown sandwich bags just for this -- yeah, yeah.. lunch jokes, i know... ; ) unless your crap is exceedingly liquid, it works like a charm, and the bag can be buried, or if absolutely necessary, placed inside a small plastic bag, tied tight & disposed of appropriately.
as a guy, i also carry a piss jar in my vehicle, usually a 1/2 gallon resealable container.
you can deduce the rest.
for bathing i use the two container method, and can bathe well (almost squeaking clean) *and* shave (head *&* face) with about 2 liters of water less if i forgo a full shave...( this method assumes you have something to carry the 2 liters of water in, so unless you have a 2 liter jug to start with, it's 3 containers.. if you have a 2 liter container, then it's 2.. see below for the milk jug comment..)
-- & if there is a reasonable abundance of fuel, H20 & space, i can take a pot bath that is damn near luxurious...
there is also a straight 1 container method, but a bit trickier.. it requires a single ~2 liter metal container.
both methods require a sponge, although a washcloth is serviceable.. the sponge, of course, holds water more effectively & creates greater flow.
the basic bath requires two containers, one being about 1 liter & metal, in which the hot water is made and another that is 2 liters to hold the mix.
if you are rubbertramping and can afford the space, then use something bigger.. when i am using just my pack gear, i use a cut off 1 gallon jug to mix my bath water & rinse water. in any case:
1) heat 1 quart to about boiling in the hot vessel & use it as a reservoir, then pour into your warm/bath vessel to heat the rest of the water...
2) dip the sponge into the bath water, then apply soap *after* you remove it.
3) Lather well... when done lathering, squeeze out the excess soap, then *pour* fresh water *onto* the sponge & apply soap to lather up again... repeat a few times.
4) squeeze out the excess soap one last time & pour fresh water into the sponge until about 1/2 full. squeeze & repeat 2 or 3 more times to eliminate most of the soap.
5) soak sponge fully, *inside* the bath container, & use the sponge, now *sopping* with fresh water to rinse.
6) if you need to shave, pour some of your bath water *back into* the hot water vessel before bathing, then when you are done bathing, you can use the bathing vessel as a shave basin.
also, if you find a place with good hotwater in a restroom, you can fill up a one gallon jug & put in in yer pack, as however stealth will allow..
that's how i do it, & if i'm carefull, even though my van is a shitty conglomeration of screws, plywood & heavy duty plastic bins, i can stealth bathe inside, when i absolutely need to.
hope this at least gives some decent suggestions..
peace,
jn