Anders_ASUSOh awesome Anders! Didn't know about that extremely useful feature! Thank you!
There's one part which you're forgetting. Auto-start-manager only tells the app that you're not allowed to start without me saying so.
But when you "close" an app in the recent apps overview, it's up to that app to decide if it really wants to close. The only way to properly close an app is to "force close" it. So we have another feature (Super clean) for this which will "force close" all the apps you deem not important when you press the "clear all" button.
To find this feature go to system settings -> advanced -> Mobile Manager -> Memory cleaner -> Turn on Super Clean mode -> enter app list and uncheck any app that you must get notifications from -> go back -> open recent apps overview and press clear all.