[APT::Clean-Installed "0";] doesn't remove packages from experimental repos

[piruthiviraj natarajan <piruthiviraj@gmail.com>]

Is there any way to clean the apt cache for the packages that I am not currently using?

I tried using this config 
root@localhost:~# cat /etc/apt/apt.conf
APT::Clean-Installed "0";
// auto-remove breaks on meta packages
APT::Get::AutomaticRemove "0";
APT::Get::HideAutoRemove "1";

// Recommends are as of now still abused in many packages



APT::Install-Recommends "0";
APT::Install-Suggests "0";
Debug::pkgAutoRemove "0";


Acquire::PDiffs "0";

// Remove apt unauthenticated warnings
APT::Get::AllowUnauthenticated "0";



root@localhost:~# 
But after doing an apt-get autoclean, it left some
 packages in the cache, for example it doesnt remove the packages that I
 downloaded from the experimental repos.
Is there anything obvious that I am missing here?