“Before I will release the code as open-source, I need to clean it up some more”

Very recognizable. I often write somewhat decently abstracted code for a client problem. The quality requirements for this stuff aren't very high so it's not 'open source quality,' and I definitely don't want it to be judged as my 'digital resumé.'

If I were to publish it it would still definitely make someone happy at some point in time though.

I've been thinking of creating the a manifesto for those cases: CRAP: Code Rushed for an Actual Problem. That way you could include it in your README and let the world know it's just a throwaway piece of code that might be useful to someone someday.