Din Djarin finally gave toilets in the Cobb Vanth (Timothy Olyphant) refers to shots as "snorts" in The Mandalorian season 2, episode 1, "Chapter 9: The Marshal" - it's unclear why writers had not yet come up with an appropriate turn-of-phrase for restrooms. Perhaps the idea of space toilets was a bit too off-putting for Star Wars creatives to think about too deeply.
Still, there have been some attempts to coin a term for toilets in Star Wars. In The Mandalorian season 1, the captured Mythrol refers to the bathroom as the "vacc tube," which presents an unsavory picture of bathrooms in space. In The Mandalorian season 2, episode 2, "Chapter 10: The enger," Din informs Baby Yoda and Frog Lady that they'll have to get cozy in the cockpit together, since the rest of the ship's integrity has been compromised by damage from the crushing weight of a giant ice spider. As he sets off to make repairs, he tells Baby Yoda and Frog Lady that if either of them have to use the "privy," they should do it now.
"Privy" is the Star Wars franchise's first decent name for the bathroom. It's not as off-putting as something like "vacc tube," but it also makes more sense that it would be the accepted term over actually just using "bathroom" or "toilet." While it is a real world word for it, it's extremely old-fashioned (and quite British), which fits with the "long time ago" feel of the Star Wars galaxy that is also filled with things like Knights. In that sense, "privy" is the ideal choice. As well as the name, Star Wars has also revealed some more details about what bathrooms are like. Screen Rant has a copy of the book The Art of The Mandalorian, which reveals more details on toilets in the galaxy. Concept supervisor Ryan Church says:
"Jon [Favreau] was very specific about the refresher. We were looking at International Space Station equipment. And then getting more and more gross with it, and literal, and odd. It doesn't matter what kind of alien you are (laughs). This has all the attachments."
The idea of making toilets in Star Wars similar to the International Space Station, only weirder, makes a lot of sense, and fits with what The Mandalorian season 1 premiere showed of the so-called "vacc tube." Shining with silver chrome, it's familiar enough to be clear what it is, but with key differences to help give it a more otherworldly feel. Similarly, it's fitting that it would be tailored to all kinds of different species, who would presumably have differing needs (though thankfully that's not been detailed...yet). Given the speeder driver's warning that "everyone dumps their gray holds out" (a reference to gray water waste that comes from buildings and households) near the port, it's likely that waste removal in Star Wars works similarly to how it does in real life.
Though the bathroom hasn't made too significant of an appearance in the Star Wars trilogies, it is mentioned a few times in other parts of the franchise. In Before the Awakening, a book by Greg Rucka following the storylines of Finn, Star Wars: The Force Awakens, Rey also refers to the bathroom as the "refresher," which is also used in The Art of The Mandalorian. While definitely a more palatable name than "vacc tube," it still lacks the imagination necessary for a term that easily fits into the Star Wars universe.
Although toilets had appeared before in the Star Wars franchise, they hadn't yet been given a name appropriate for the space-faring franchise until The Mandalorian. Jon Favreau's series has only been further building upon George Lucas's world, so only time will tell what new terminology might be discovered next.