I dropped my cell phone once (the water was clean!). For me, that's cataclysmic. It was the end of life as I knew it (I was so dramatic). After about a month, all the post-water glitches went away and it was as good as new again.
I have also dropped my ben wa balls on numerous
occasions. School bathroom, personal bathroom... I use the really tiny ones, so they come out more easily. Once, I was staying at a friend's housing complex and I dropped one in the toilet of a guest bathroom. My partner and I tried to fish it out, but it was stuck in a perfectly-sized hole that would be the last place I ever saw it again. I'm pretty sure it's still there, and rattles every time someone flushes!