I had the pleasure of seeing Journey in concert (with St. Augeri) three times and apart from the first show in 1999 the following shows he defenitly had vocal problems and with Castronovo's "help" the shows were saved.
BUT......I know from a very reliable source that most of the vocals for the 2001 official DVD have been re-recorded since Augeri had one of the worst nights on that perticular evening. Anybody who was at the show might be able to confirm this.
So it seems that the Journey camp actually used that "method" before.