I fell for the marketing ploy and bought one of those automatic sprayer things for my shower -- the one that has the maids in the commercials. It sounded like a great idea. However, in real life, it falls short -- literally. I have it in a bath tub with a glass sliding door. The back wall and first foot or two of the door is clean, but the rest of the tub don't get sprayed. It might work in a smaller walk-in shower, but doesn't do much for a bath tub.
I'm going to throw it away when the liquid is gone. I guess it's one of those "sounds too good to be true" life lessons.