The easist way to get hot water for washing is to put a little water in the dirty skilet with a few drops of soap, put it on the burner for a minute, and then let it soak. No waste. I learned that one camping 40 years ago! My last boat had an instant heater, and still, that is how I did most pots. So easy.
Plus the pan or pot becomes "the sink" from which you wash all the other dishes, washing the pan last. It uses a lot of water to put just an inch of water in any sink, so don't. Let the pan be the sink. Tertiary benefit: if you are careful, this method keeps the sink clean(er), so you don't need to use MORE water to clean the sink.
For rinsing, we didn't have a spray bottle (fabulous idea!), so I used an old plastic bottle that previously held dishwashing liquid. The amount of water coming out can be as little as a dribble if you don't squeeze the bottle, and beyond that things are very controllable with "squeeze force" (or lack thereof). It's also instant off, so you don't lose any precious drops in the 1.7 seconds it would take you to reach for and turn a faucet off. Our bottle was clear, so I also had constant feedback on how much water I was using to rinse a meal's worth of dishes.