Water conservation is very important. You'll need three dish pans to do this. The first rinse will dilute the salt water from the wash, and the second fresh water rinse will eliminate any trace of dish soap or salt. Air dry dishes and utensils. Joy, dish soap works especially well in salt water.
Bathing can consume an enormous amount of water.
Inflatable solar shower privacy enclosures are available at a very modest cost. Use burlap bags to make a porous floor for the shower if you don't like sandy feet. Bathing in salt water is common. I like to do this after dark, so my soap bubbles aren't so noticeable. I've found that this practice is the norm rather than the exception.