We throw "BTW this or that..." several times a day, it's obvious that we can, sometimes via DM, sometimes on specific or generic channels, depending on who we think might be interested in it. Knowledge propagates, discussions ensue, sometimes the original topic devolves into something else and ideas are born.

That's on top of a ~1h tech sync meeting every other week, where anything goes, questions get asked, ideas get challenged, notes get taken.

It works. In my experience it works better than watercooler because it's non-interruptive, scales across TZ, and everyone gets a chance to jump in or catch up later.