I’m planning on embarking on a multi- day fast (3-4 days), but need to be able to talk well for work meetings. How severe does it dry your mouth and does it in any way impact your ability to speak at length (30+ minutes at a time)?
3-4 days you will be fine. The most important thing is to breathe through your nose at all other times. It’s when you get to more extended fasts (like 6/7 days) that you may notice challenges in speaking - but this is completely based upon how much you talk during the day, so it’s quite variable.
I’m currently on day 5 (of 10, 15, 20?). My previous 7 day didn’t have any challenges in this department. I still produce enough saliva to talk normally throughout the day. For part of my job, I talk on the phone a lot.
I forgot that some people are mouth breathers. Many years ago, I focused heavily on conditioning myself to breathe correctly, and deeply, through the nose. It’s a great point that I seem to overlook since I view the world from my own personal lens, and forget that not everyone behaves in the manner that I do.