If you are aware of wordpress working, you must already wondering how long it will take to delete 10000 spam comments when only 20 comments can be deleted at a time. Well the only option is to delete these comments with a SQL query which will delete all the entries flagged as pending from the table comments. Here is a sample SQL query that will do such a job in wordpress,You can easily run this query from phpmyadmin interface, only problem is that one needs to be comfortable with such technical stuff. Also this is not the easiest workaround. I decided to search for a better solution for this and if such solution was not already there, I was planning to create a simple WordPress plugin which will do the required job. Fortunately, after doing a bit of googling trying few plugins I found a reasonably good plugin, aptly named as " Delete Pending Comments". This plugin is easy to use and does the job neatly and quickly. All you need to do is to install it and just press the link <delete pending comments> from comment menu. This plugin is not the optimum one though, I feel that it lacks certain essential features which could had made this plugin a real useful one. Firstly there is no customization available within this plugin. All it does is to delete any pending request. A date range for deletion of pending request would have been handy.
One of the difficult tasks in maintaining a blog is to delete spam comments regularly. As your blog gets more and more traffic, it becomes target of spam bots. Unless you have real good spam filters, even your moderately successful blog can be flooded with hundreds of spam comments in a day. For past few weeks I was busy preparing competitive exams and during this period my comment approval queue was more than 10000. Now as there was no feasible way to check all these comments to filter out genuine comments, I decided to clean the queue by deleting all the pending comments.