public function _clean($pMax)
    {
        Agl::validateParams(array(
            'Digit' => $pMax
        ));

        $old = time() - $pMax;

        $collection = new Collection(self::DB_COLLECTION);

        $conditions = new Conditions();
        $conditions->add('access', Conditions::LT, $old);

        $collection->load($conditions);
        $collection->deleteItems();

        return true;
    }