I also find a side benefit of writing about what you're doing (or talking about it) other than visibility and education is that it makes you understand it better as well in a very tangible way.
I've not had a great deal of success with encouraging others to start doing this, but I still find that the impact my own work has within the company is greatly improved if I have somewhere that I can write about it.
I don't expect others to actually read my internal blog on an ongoing basis, but I get a great deal of value out of being able to send links to posts on it to people. I wrote up a big essay about how to use our internal analytics tool once, for example, and shared that with anyone who asked how that thing worked.
I've used a few different mechanisms for these:
- A Slack channel. Free to setup, anyone who wants to follow along can join the channel.
- A confluence blog - confluence has a "blog" feature which you can just start using.
- An organization private GitHub repo full of markdown files.
I did eventually publish the internal blog posts I wrote at one organization (an organization which has since shut down) - I shared those here: https://simonwillison.net/series/vaccinateca/
A project with a published write-up unlocks so much more value than one which you complete without giving others a chance of understanding what you built.
I've maintained internal blogs (sometimes just a Slack channel or Confluence area) at previous employers for this purpose too.