The 'Delete All Comments' plugin is built to delete all comments (Approved,Pending,Spam,Trash,Post-Trash) from wordpress database easily.
Plugin found under
Tools > Delete All Comments
Just a standard installation required.
- Plugins > Add New > Upload > 'delete-all-comments.zip' - Install Now
- Unzip & Upload 'delete-all--comments' folder to the '/wp-content/plugins/' directory
- Activate the plugin through the 'Plugins' menu in WordPress
- Delete All Comments plugin is under 'Tools' menu