Hi!
Up until the last month it was either a spray bottle shower or This is gonna sound weird. Buddy would stand on this huge stainless Dog bowl that I'd fill w/ water (like it was a inner tube or a boat) then I put the tub on. Between me using a cup/small handled plastic bowl to (sort of spoon) water over his back ect... Never in the head. I'd use the spray bottle for that.
I will say the spray btl. took time. I think when he was a baby it may have been a punishment. I had no way to know for sure. Back then most information came from books re: birdys. If my Dad did this it was from lack of knowing better.
Anyway. Maybe you could just use the spray btl. to do his feet. I can tell you w/ the tub he'll be able to open his wings if you have him facing you.