You can sync your Facebook calendar with CalenGoo via Google Calendar: Sign in to Facebook, open “Events” and click “Export events”:
You should get an URL that starts with “webcal”:
Sign in to Google Calendar and click “Add”, “Add by URL” on the left under “Other calendars” and enter the “webcal”-URL:
Afterward your Facebook calendar should appear as a normal shared Google Calendar. It will appear in CalenGoo the next time you sync.