I have a Scrubbing Bubbles Shower Cleaner.
First, if you have a full-length tub/shower set up, the device will not fully spray to the back of your tub/shower. It's reach is just not that far. This thing works best for the stall type of shower.
Second, if you have a shower curtain hanging inside your tub, it will spray the shower curtain. The solution will not be able to get up under the shower curtain. If you hang your curtain outside the tub, the solution "may" drip down. I only say it might because, really, the thing does not spray out a waterfall of solution. It's a pretty light mist.
Lastly, my shampoo bottles, etc, have been sprayed and there seems to be no problem. I keep my razor on top of my shower door, so I don't think it gets sprayed.