asterisk users - Sep 2005 - Using *0 to flash an external trunk on bridged channel

Anybody had success using *0 to flashes an external trunk on bridged channel?

The "Asterisk vertical service activation codes" section of the Wiki
(http://www.voip-info.org/tiki-index.php?page=Asterisk+vertical+service+activation+codes)
indicates that *0 can be used to flash an external trunk on bridged
channel.  Nothing seems to happen when I use it though.

Do I need to do something special in extensions.conf or perhaps
features.conf to get this to work?

Thanks,
Hugh