This should help you count the posts of individual users after you delete the offending posts:
SELECT COUNT(*) FROM w3t_Posts WHERE B_PosterId = 'member#'
It should give you an accurate count of posts from that user in the db. It won't help with mass changes but will stop you from having to count the posts manually.
Donate to UBBDev today to help aid in Operational, Server and Script Maintenance, and Development costs.
Please also see our parent organization VNC Web Services if you're in the need of a new UBB.threads Install or Upgrade, Site/Server Migrations, or Security and Coding Services.