If you recieve no answer within a few hours your question easily drowns as new questions float into the never ending stream.
Hence, your question is outdated really fast - and keeping it alive by editing seems like a hack rather than a solution to the real problem: unless the question is found by the right user within a couple of hours it dies.
Therefore, I suggest two things:
- The oldest unanswered questions are shown at the top as long as no answers are entered
- After 24 hours, unanswered questions are paused until the user confirms that they are still active
This would lead to greater chance of getting an answer - and the pause / delete function would clean up the list and remove 'noice' from the list