Clear cache and custom rewrite rules

I’ve got my custom rewrite rules defined like this:

add_filter( 'rewrite_rules_array','my_rewrite_rules' );
function my_rewrite_rules( $rules )
{
	$newrules = array();
	$newrules['free/([a-z-]+)$'] = 'index.php?price=0&platform=$matches[1]';
	$newrules['free/([a-z-]+)/page/([0-9]{1,})$'] = 'index.php?price=0&platform=$matches[1]&paged=$matches[2]';
	return $newrules + $rules;
}

I would like to clear the cache for the folder “free” (and all it’s files) programatically. Is that possible? w3tc_pgcache_flush_post() only works for posts.

http://wordpress.org/extend/plugins/w3-total-cache/