During drycamping (boondocks or otherwise): We use pre-moistened towelettes for washing the hands, the face, and the rest of the body.
During drycamping (boondocks or otherwise): For the toilet ... when it's brown -> flush it down, when it's yellow -> let it mellow.
Using these and other conservation techniques, we can stretch to about 5 days of drycamping based on our built-in tank freshwater capacity. We can go longer based on our grey/black combined tank capacities ... hence my comments earlier in this thread about built-in RV fresh water capacities being equal to, or greater than, combined grey/black tank capacities. The reason I say "equal to, or greater than" is to cover freshwater losses other than into the grey and black tanks - such as losses through body sweat, cooking evaporation, humidifier usage, etc..
FWIW, we are in the 3rd or 4th year of a California drought that has become serious enough such that both the springs and the well supplying our residence are way down from their historical fresh water deliver rates ... the camping fresh water conservation methods I mention above are now almost as fully enforced when we're living in our residence.
You can't have too much freshwater along in your RV during drycamping treks - only more than you can find room for, or more than your RV's chassis can carry weight-wise.
