How can unused tracks be removed from the NLA?

With autokeying enabled I accidentally moved a few objects, unfortunately they now appear in the NLA editor. I removed the actions saved and reload but I can't get rid of the entries.

• When we create a node group and animate something inside it, a new Action is created and appear in NLA as an Action (not yet track). When we ungroup the group... or clear keyframes, most of times, it disappears, sometimes, it doesn't. And here is where we would need to delete the empty Action. You can do it with Blender console, like this: bpy.data.actions['CompositingNodetreeAction.001'].clear_user(). Maybe you want to delete it, but I prefer to reopen the file. See this [screenshot] (pasteall.org/pic/index.php?id=108866) before deleting the Actions. – Mario Mey Nov 18 '16 at 2:54
• Be careful when using D.actions['CompNodetreeAction'].user_clear() and removing the Action like D.actions.remove(D.actions['CompNodetreeAction']... you can make Blender crash (it just happened to me). It's better only to clear users and see what happens. Maybe you are using that Action somewhere else. – Mario Mey Nov 18 '16 at 3:01