[James Birkett]

Hey terminator,
I personally wouldn't recommend getting something automated to clean up your database, it could cause issues. It depends on how you want to find the spammers. It could be as easy as just running SQL queries to select spammers and displaying them as an array.
I'd recommend (using a new page) doing a mysqli and connecting to the database then running the query and displaying the results as an array, then running a query to delete them entries.
You'd need to define conditions of spammers though.. it's hard to really make a query to find spammers.
SELECT * FROM `user` WHERE `joindate` >= {date in database format} AND `postcount` >= {postcount}?

I am unsure of the best way to do this.