Okay, here’s one: Electric toothbrushes.
Presently I have a Sonicare something or another, and before that one of those Crest things with AA batteries. And for some reason, I can’t help but keep noticing—even though I’ve noticed so many times before—that the automatic motion of these things is inadequate to clear the excess water. That is, you might think you can simply rinse it out, and then run the thing for a couple of seconds to spin or vibrate out the excess water, but no, I still have to shake the damn thing like an old-school toothbrush to get the water out.
Random enough for you?