I'm thinking of getting a foam gun to aid in the washing process. I have watched a few videos but have this question. Do you need to switch from the foam gun to a regular nozzle to rinse or can you switch the foam off and rinse with the foam gun still connected? It would seem like a lot of effort to swith the foam gun out for every panel but in the videos I'm watching the user always seems to be rinsing without the gun.