This required 10% positioning 10% luck and 80% patience.
Im very sure with more aggressive Ghost useage and some luck Bronce is very possible. but since Bronce is faceroll anyway and you cant really use the Ghosts to get gold easier its a kinda unimportant exploit.
This exploit wont help anyone to get a Gold Medal faster, since stacking the ghost will always take way more time than just killing the mobs yourself with 5 people.

Im not really interested in soloing Challende Modes because most of them just dont work complety because of a specific boss or trashpack. And the Challenge of a Challenge mode is to do it IN TIME with 5 people. Soloing it with all cooldowns on any trash + as much time as you want makes it kinda pointless in my opinion.
The reason i still make this video is that i just wanted too see how far i can get with exploiting the ghosts on challenge mode. Almost always when i got this instance as Random heroic i used 1 ghost to kill the first 2 bosses a bit faster but i always wondered how far i can use them to help me clearing that stuff.

song: http://www.youtube.com/watch?v=jECSBjZwo7w