On one of my wordpress blogs, I ran into an issue where there were 4000 plus comments that were all spam, and I couldn't get rid of them due to time constraints. I had this issue for months. Then I finally loaded the builtin spam filter, and when I tried to run it, it crashed because it couldn't handle that much spam. Weeks went by and finally last night while watching Cloverfield, I realized that I knew how to use myPhpAdmin, a mySQL administrative tool. We learned all about mySQL in college. So after figuring out which DB mapped to which blog, I then browsed the comments and found the stash of 4000 spam comments.
The sql browser enabled me to set the view to 1000 or more entries at a time, so I chose 1000 and began deleting everything after post 50. I killed them all but 500 and let the spam filter do the rest.
I may do a tutorial with screenshots eventually because I can't be the first person to have this problem.