When I worked in RVs, an old camper showed me the spray bottle trick.
It saves a lot of water washing dishes, but we put the soapy dishes a rack in the right-hand sink and just use the spray head to rinse them all when done.
A coupla squirts of soapy water in the toilet bowl after adding some water before use will prevent skid marks that usually require the toilet sprayer to remove.
It's also good to take in the shower. One of the problems with Navy showers is with me and the wash cloth drying up between wetting down and rinsing off. The spray bottle of soapy water keeping the wash cloth wet is just enough to finish scrubbing without having to wet down again.