No LO package is installed, but LO files are still present. How to remove?

Running “sudo apt-get remove --purge libreoffic*” was my last-ditch effort to remove loads of libreoffice files, but still left me with a ton of them.
Short of reinstalling Ubuntu, is there a way of removing these many leftovers?
from /home/ken/.config/
from /usr/share/app-install/desktop and …/icons
from usr/share/application-registry/
from /usr/share/applications
and from several other places?

What’s a body to do?

If I agree with myself that I do not have Libreoffice installed (currently) is there any danger if I issue “locate libreoffice” and then follow the resulting trail to delete every instance of every found file line by line? Seems like a chore, but if that’s what it takes, so be it.

All this happened when I installed 6.0 and found that 5.x was still on the machine, having been installed from the LO website, not through Ubuntu’s Software Center.

Everything installed through apt is tracked by apt and can be removed by apt. Everything custom installed can’t be removed by apt. If the custom installer doesn’t provide an “uninstaller” (something like make uninstall if you compile it yourself), your last resort is your sketched procedure: locate files and remove them manually.

Personally, I always installed LO from my distro and never tried from LO site; Consequently, I have no idea about features of the install script.

I use SYNAPTIC to manage my LibreOffice systems on Linux-Mint Mate (Eng-GB). I normally have two versions installed from the LibO website. At the moment it is 5.4.5 and 6.0.1.

To remove a version using synaptic, for example to upgrade, I alway remove the version to be replaced first. In synaptic 5.4 will show up all the LibreOffice 5.4 files. Be aware that there are TWO sets of libraries to be removed. For example libreoffice5.4xxxxxx and libobasis5.4xxxx. Removing libreoffice5.4xxxxx will NOT remove the libobasis5.4xxxx libraries.

LO’s download gives instructions to open a term in the downloaded directory containing a supply of libr*.deb files and invoke dpkg -i against them all in a wildcard fashion. That does the installation for sure, but as you suggest, APT hasn’t a clue as it wasn’t involved in the installation. Trying to remove via apt is fruitless; Synaptic is more entertaining, but still leaves all manner of files scattered throughout the file system.
I guess the only way to win is not to play, as some computer said long ago. Anyway, thanks for the help!