Is this really a Halo 3 cheat?: Cortana wearing b--b tassles w/ a secret achievement?

[NarutoChick]

I've hear there is a secret achievement for Halo 3 where after you rescue Johnson and take the Hammer from a Brute that you "jump of the ledge all the way to the right, while pressing A,B,B,A,X and down on the D-pad, you will see Cortana pole dancing with tassles on." Tried it but what Ledge? Is this even a real cheat? Thanks

 

[Brandon]

kinda sick that you wanna see that.....but I dunno