There is only one time when you wash out the inside of your car with a garden hose: when you truly, absolutely do not give a single fuck about your car anymore.
This guy knows how to wash his car, requiring only a hose and a sponge. And you guys spending hundreds on products, microfiber and polishing tools.
He says in the video "I just wait half an hour and then I start it and it goes".
See? All natural, no chemicals, no abrasion. Just water, love and some lettuce on the roof.