Here's a simple way to use voting to clean up some crap:
- In the search box, enter: votes:0 answers:0
- Click the "Newest" tab and scroll down until you're looking at questions that are at least a day old
- Click on one that looks bad (based on the excerpt), read it.
- If it really is bad, vote it down.
After 30 days, questions with no answers and negative scores are automatically deleted.
The "official" meta post with the auto-deletion rules was recently updated: http://meta.stackoverflow.com/a/92006/130540