My preference would be to try distraction rather than the quake. It can be counterproductive, as she may have begun to learn this behavior because of uncertainty over whether the offered "perch" was stable and safe. If you quake her, it proves that its not safe. I think ingrained, learned biting behavior (particularly with a Zon) might be the most difficult to change. One alternative approach is to offer her something that is ok to bite (like anything other than your flesh

), when stepping her up, like a "bite stick".
When dealing with a tough question like this, Mark, it might be good to consider talking with a behaviorist who is experienced with Zons. Someone who is used to dealing with Zons with 'issues', you know?