Siri achieves general unintelligence

A lot of people knock Siri's implementation as more or less a dialog tree of magic phrases one can utter to achieve a discrete set of tasks, but one that I just can't get my head around is Announce Notifications. You can tell it to stop announcing, to start announcing, and to pause/mute them for an hour or for the day. But in my most recent thirty attempts, Siri only successfully muted announcements for an hour one time. Usually it mutes my phone or, more recently, does nothing at all.

Every time my ears are inundated with text messages and calendar events I don't care about, I try my damndest to remember what it is I said to get Siri to temporarily back off, but I'll be shocked if there's a consistently correct answer. Ask the same thing five times and get five different results.