That's amazing and specific experience, very cool!
One thing I noticed at the top of the article was that they used the steam as a source of fresh water as well, did subs do this too, when you worked on them?
They alternate between the two sections, so they do one stack every 2 hours and you can see how much labour, 2 man less than 5 mins. Remember, this isn't how they run it all the time and it is the backup system. With that in mind, most backup plans for anything if not a like for like, are always more intensive. Compare writing a letter by hand too sending an email in effort and this, for me, this looks way easier.
Worth noting that even in the vid, you have crew members of senior rank watching on as they have never seen it done before, which indicates how uncommon it's usage is.
Ah yes, was referring to the excess drinking water aspect knowing electrolysis upon sea water will produce chlorine due to the salt, which really would be an emergency in itself.
Glad to hear you didn't have a situation to use one and does seem a very rare situation, but neat that there is a solid backup.
You might find this series from Smarter Every Day interesting. https://www.youtube.com/watch?v=g3Ud6mHdhlQ I didn't find a bit about how they make drinking water, but here's an episode about how they regenerate their oxygen on a nuclear sub.