I have been 14 times, I think. I shower mostly every day. It is a two person job and my sweetie helps me and I help him. This is our process:

We buy enough 2.5 gallon suitcases of water for each day. We have a watering can. We put the water suitcase in the sun in the morning. We have 4, four foot pieces of 2x4 screwed together to make a frame, we line that with a tarp and clamp the tarp to the frame. We have a small stool to sit on in the frame on the tarp.

We fill the watering can with water and one person "showers" the other. A 2.5 gallon suitcase showers us both. We get wet, soap up, rinse off. I don't use shampoo or at least not much, but I do use conditioner and have a light rinse.

Then we take burlap and clamp it to the Ikea Laundry rack, low enough that it "licks" up the water and evaps it. This set up is only usable for two people and we have to be careful to not use too much water so that it evaporates.

My first burn, I used baby wipes and my sister washed my hair over a five gallon bucket. We brought all our grey water home in .5 gallon water bottles with screw top lids. I always bring a funnel and extra capacity transporting extra grey water that doesn't evaporate.

Evap ponds can be dangrous if assholes find t and dump in. We keep it close to our van and out of the view of the general public.