At some point you may end up with a number of control sites that you don't use any longer.  

How can you identify if a control is no longer used, and how can you clean up and remove such controls?

Controls that are not used on any course are shown in orange color in the controls list in the Navigation Bar.  There is also a menu item Highlight Unused controls that highlights in red color the unused controls on the map.  This enables you to quickly identify such controls.

In the Control menu, there is an item Delete all unused controls.  This option allows you to delete all the controls that are not used on any course.