Portlet without navigation panels

I want to show an anonymous portlet without MWS portal navigation panels (header, footer and left navigation)
It works in anonymous sessions but if the user have logged in previously, the portlet is shown with navigation panels.
How can I avoid this?

Create a new shell rule that uses the Blank Shell for your specific page. Make this new rule first in the rule list.

To do this:

  1. As sysadmin, navigate to the shell rule editor ( Administration Dashboard > User Interface > Manage Shell Rules )
  2. Click ‘Create New Rule’ tab
  3. For the Rule Condition, use the ‘Parent Resource’ button and specify your anonymous page (or a common parent folder if you have multiple pages).
  4. For the Rule Result, specify the Blank Shell.
  5. Save it.
  6. Click the Change Rule Evaluation Order tab
  7. Move your new rule to the first position
  8. Save it.

Thank you very much.