Custom sidebars for post types

Hi there. A while back I posted this question:

Recently, I noticed that sidebar.php has a new filter call in it:

Line 44: $custom_sidebar = apply_filters('avf_custom_sidebar', $custom_sidebar);

I’ve been trying to figure out how to use it and I’m not getting it. Can this filter help me apply a specific sidebar to a specific custom post type archive or individual post? If so, can you give me a shove in the right direction for how to make this work? :-) And, if not, can you give me an idea of what this filter would be used for?

Thanks!