Grunion_Contact_Form_Plugin::daily_akismet_meta_cleanup PHP Method

    public function daily_akismet_meta_cleanup()
    {
        global $wpdb;
        $feedback_ids = $wpdb->get_col("SELECT p.ID FROM {$wpdb->posts} as p INNER JOIN {$wpdb->postmeta} as m on m.post_id = p.ID WHERE p.post_type = 'feedback' AND m.meta_key = '_feedback_akismet_values' AND DATE_SUB(NOW(), INTERVAL 15 DAY) > p.post_date_gmt LIMIT 10000");
        if (empty($feedback_ids)) {
            return;
        }
        foreach ($feedback_ids as $feedback_id) {
            delete_post_meta($feedback_id, '_feedback_akismet_values');
        }
    }