Clear cache cron

add_action('template_redirect', function(){
    if (isset($_GET['clear-cache']) && $_GET['clear-cache'] == 'a3ef456de32e' && class_exists('Swift_Performance_Cache')){
        Swift_Performance_Cache::clear_all_cache();
    }
});

// Set a real cronjob: curl "https://yoursite.com/?clear-cache=a3ef456de32e"