Best approach for scripted toolbars?

Hi,

In my application, I wish for my users to be able to create toolbars (DockableToolbar) from their own scripting code. This works fine, but once the user exits the application, the newly created toolbar is saved along with the ordinary toolbars, which I don't want. What's the best way to prevent the BarManager from saving the toolbar? I've looked for a property that might tell the BarManager not to persist it, but I can't seem to find any.