It does do something but your hand is not attached to the staff. You'll need to make the model with the hand.
That shouldn't be necessary. Just place the mount point correctly, and you shouldn't have any problems.

The item will be orientated as it is in the actual model file when it is spawned over a brick, or when it is a "thrown" item. The orientation of the
mountpoint defines how the model will be held by the player model.
Of course this is assuming you are using Blender. Things might be different in another modeling software.