Proper way to destroy.

[mas-dude]

I am trying to find a way to properly destroy the application and the router but can't seem to find any destroy events.
I have some pretty bad memory leaks under IE9 and thought the application would be a good place to start to destroy stuff.
I do not have this problem in Ext 3.4, but since I am using the MVC framework I am wondering if it could be the cause.