Nemo Helio LX that I use for showers, rinsing dishes, brushing teeth, etc. If the water isn’t warm enough from sitting out all day in the sun I just add in a kettle of boiling water and mix it up. You can fill it from any water source you feel comfortable showering in, but I’ve only ever used potable water since I use it for teeth brushing & in a pinch if I ran out of my regular drinking water I could drink it but it tastes a little rubbery.
It’s ~6 gal capacity and the fact that it’s just a rubber bladder makes it like carrying a dead body when full, but I’m sure the regular Helio at 3 gal is a little more manageable albeit less capacity. Also at the end of the trip when it’s empty it packs down pretty small
Just got the Cabela’s deluxe shower tent (basically a mini turbo tent) that I used for the first time this weekend. It’s pretty big packed but very sturdy and 5’x5’ inside.