How to clean up PackageKit in Fedora OS the right way !

Question
Is there a proper way to clean up old PackageKit caches without resorting to low level sudo rm -rf /var/cache/PackageKit/2[3-4] etc.

Answer

The man pkcon, and  PackageKit does not seem to provide a command to clear the cache.

The best method is to tell PackageKit not to cache that is store packages at all. This can be achieved here

/etc/PackageKit/PackageKit.conf: uncomment #KeepCache=false (to make it look like: KeepCache=false)

And if you use dnf to update, you tell PackageKit not to download any updates automatically:

gsettings set org.gnome.software download-updates false

Also in Fedora 26 and above,

I found that pkcon refresh force cleared out PackageKit-cached RPMs that were from currently-enabled repositories and had already been installed elsewhere, that is via DNF !