ghost of glohnor? time spent spawning him

[syztem]

curious how many of you have done this, killing the fallen erudites to get him to spawn. ive read various p99 + allas and other guides, people ranging from 1 to 15 to 30 cycles(at 22mins a respawn). so basically theres around 7 fallen erudites total if you kill them all, giving you a shot to spawn the ghost to turn in dark shroud and get him to pop in crypt to kill for head/wrappings yes?

what type of experiences have you guys had time wise spending down there to get the trigger mob to pop?