I've just noticed that you can load any orbeon forms with the following parameter:
To load the page without the Orbeon banner and navigation.
You can also make modifications to epilogue-servlet.xpl to create a case for specific pages. For example, I've created a page called xforms-submit and I want to load that page using the plain theme (theme-plain.xsl). Editing /config/epilogue-servlet.xpl (on line 56 in v 3.6.0) and adding this rule:
Achieves the desired effect.
So after adding this, my line looks like this:
- ► 2011 (35)
- ► 2010 (43)
- ► 2009 (37)
- ▼ April (3)