I know of How to remove an uninstalled package's dependencies? and I tried
apt-get autoremove
but that does not remove dependencies that are recommended/suggested by other packages.
That is, if I install a package X that recommends Y, but I do not install Y, and then I install package Z that depends on Y. and later I do
apt-get remove --auto-remove Z
then Y is not automatically removed even though nothing depends on it. (X "picked up" Y, even though it does not depend on it).