Open-sourcing of code is not a beauty contest. And, IMO, there's no need for the code to be "convenient for collaborators" before open-sourcing.

The main thing that open-sourcing does is make it possible for others to pick up the project if you disappear, even if that is not easy. You can release it now, but with a clear statement that the code is currently not in a clean state, and ask for contributors to wait till you finish the cleanup before they make changes. I'm sure everyone will respect that request (truth be told, it's not even easy for most opensource projects to attract new developers).