This is a little code snippet from php manual:
putenv(\'LC_ALL=zh_CN\');
setlocale(LC_ALL, \'zh_CN\');
bindtextdomain(\'domain\', \'./locale\');
textdomain(
The solution for me was to save the files with a different name, using the date for example, and then changing the domain:
#the path for a domain, the .mo files must match the domain
#the trick to avoid permanent caching, is to use different names for the domain, like the date messages_180320151250
$domain = 'messages_180320151300';
#sets the path for a domain, the .mo files must match the domain
bindtextdomain($domain, $_SERVER['DOCUMENT_ROOT']."/apps/cp/locale");
textdomain($domain);