I have never heard of shuttle mediation - I have to admit it made me chuckle a little bit picturing the scenario:
"She said what?! Well you go back in there and tell her this!"
I have a very dark sense of humor sometimes =)
My best friend got divorced this way. Took all day with the back and forth but she never had to see her ex. I'm 100% NC so if I end up here this is how I'd want to do it.