You see how he is sweaty and worked up in this one? They were probably messing up the recording over and over as he was trying to get his lines out, manipulate the rag, and sync both of those up with the plane dives.
They are always very very careful to when manipulating objects during the Zero G dive effect, they never let anything get too far from there hands or bounce of the walls or freely move about because it would become too easy to see it for what it is.
They do Zero G dives, or segments with regular Harnesses that they edit the wires out of.
In this video you can clearly seem them manipulating their harnesses and wires.
[video=youtube;l4D3PLNZp2E]https://www.youtube.com/watch?v=l4D3PLNZp2E[/video]
Sorry for the language