I had the same situation and found a great solution.
I bought a male adapter from ACE Hardware.
13/16" x 20 Thread.
It will screw on to your faucet, (once you remove the housing for the screen.)
The bigger thread will screw on to any garden hose.
I got a 4' long hose. Anything longer will tax your battery as the water pump works harder to maintain the pressure.
I bought a lever activated spray nozel attachment, with 5 different settings.
Set your desired tempature, and leave your water pump on.
It works great!