A year and a half ago I was debating what to do on the walls of the small bathroom in our classroom. I hated having that wasted space and I felt like the kids could have something there they would enjoy and/or learn from. The comments in response to my request for ideas were wonderful. I ended up just hanging some artwork last year, which I liked. I added more artwork this year (we needed more than just Picasso, Escher, and Khalo). Then, I decided to add the words the kids are expected to learn in kindergarten. Of course they haven't all learned them yet so I figured they might as well see them often.
Now, in those emergency situations when I actually use this bathroom it feels less gross and icky to me. Not un-gross or un-icky, just less so. I did manage to take pictures that avoid anything that shows this is a bathroom. I promise it is.