How can I clear the Varnish cache? We have installed node queue module on Pressflow 6 + Varnish. For clearing the varnish cache for node queues, we developed rules using the Rules, and Cache action modules. Whenever we update the content, it is reflecting for logged in users, but it is not reflecting for anonymous users.

Could you please suggest us for how to clear varnish cache with rules or any custom code?
The Cache Expiration module is designed to clear items from caches, including Varnish. 


  This module acts as a grid to detect and act upon events that will expire URLs from caches like reverse proxy caches. The Cache Expiration module is a spinoff of the expiration code of the Boost expiration code so other modules can use it. This module stands on its own and does not use Boost in any way.