Op 08-03-17 om 19:01 schreef Richard Owlett:
What is the most effective way to completely remove an application?
Remove it - as you did - including the configuration files (i.e. any files in /etc). Then check your home directory - also ~/.config and ~/.local/share - for any user owned configuration files and directories that might have been created by that application. The package manager will not have removed those, because it isn't allowed to touch anything in the user's home.
Regards, Frank