Not exactly a public setting -- but in the lab, I use raise-to-activate Siri on Apple Watch for setting timers and doing basic arithmetic (e.g. "what's 3% of 42 ml?"). It's been really helpful, since I have to have gloves on at all times.
The most awkward time is when the raise-to-activate doesn't work for whatever reason and I have to say the same thing again.
Only with these two pieces of info we can decide whether it's feasible to use voice assistants in a lab setting.
I think people quickly grasp the reason why I'm doing it -- we all wear gloves, so the benefits are obvious to my fellow labmates.