You don’t really need to see any toilets in the Star Wars universe any more than you need to see a hobbit go relive himself behind a tree in the Middle Earth. It’s pointless, kinda gross, and doesn’t really add anything to the plot. In certain films set in the real world you can get away with it because it’s something that relates to real life. In an epic fantasy setting however, including “a galaxy far, far away”, it would just be weird and distracting.
One series of novels I read back in college did have a great joke about a 20th century character trapped in a mostly medieval magical realm, having a horrified reaction to finding a chamber pot under their bed. Fortunately for them, the castle also had modern plumbing for it’s temporally displaced guests.