Ours is a tub enclosure with shower doors which is tight as well. Our shower has a Tee with a button and I can choose the shower head or the hand held. Works out quite well. I wish the hose was longer but it gets the job done.
We also have a small screen to catch the hair so it doesn't go down the drain and clog it.
I also find the massage function on the hand held penetrates the undercoat better and they seem to enjoy it. Just stay away from the nether regions with the massage functions.
I would venture a guess that you could purchase a Tee and cheapo hand sprayer for about the price of a tank of gas.
I usually don't wash them outside unless its the dead of summer. The water temperature is cold and I want the bath to be a good thing, not traumatic.