I have a semi walk in shower with a door. The door keeps the dog from escaping. When I wash him (with the handheld showerhead), I'm expecting to get wet also, so I wear a swimsuit or shorts. It's the easiest place to wash him because I place a hair catcher in the drain and rinse off the sides easily after washing the dog. Very little cleaning to do afterwards. I always wash him just before I take a shower myself. I'm already wet anyway, so no big deal.
In the summer, I washed him outside a few times with the hose. That's a battle. Unfortunately, I don't have a place I can tie him so I need another person to hold the dog. It's a whole hassle so I don't do that anymore.