After a while the Joomla redirect links table tend to be cluttered with a lot of links, and you might want to remove all these as a part of your maintenance.
To clean out these can take an awful long time, and after these are deleted, you need to do the same again to clear out the trash.
However, the easiest way to clean out all these links and empty the redirect manager table alltogether is to simply empty the table #__redirect_links by using phpmyadmin.