Whistle : What's the best way to include custom channel variables to a callflow?

[Alan Evans]

Hello,

I'm looking into how to add FS Channel Variables (http://wiki.freeswitch.org/wiki/Channel_Variables) to a whistle callflow.
There doesn't seem to be a generic way via Winkstart so I'm guessing I need to edit the underlying couchdb document directly.

Should I place the config in the callflow or the Device document?

Are there any examples of how to do this?

Thanks
AlanE