Yes, please do :)
Asking questions that you already know the answer to is fine, in fact it's encouraged (I'm quoting Can I answer my own questions, even those where I knew the answer before asking? here).
As long as the post is phrased in the style of a question (e.g. How can I recreate Organic Groups on a more basic scale?), and is on-topic/useful to the site (which I'm sure that particular question would be), then it would be a valuable addition to the site.
You never know, you might even get an answer from someone else in the community who's solved the same problem in a simpler way. Everyone wins really!
Also see Posting and answering questions you have already found the answer to, in which the fabled Jeff Atwood himself encourages people to do this. I think this second question is actually a far better example, the OP is basically asking the same question that you have, just not about Drupal in particular.