O pacote dpkg -P deve limpar o pacote totalmente, incluindo os arquivos de configuração. A seguir, a descrição da opção do comando man dpkg
-r, --remove, -P, --purge package...|-a|--pending Remove an installed package. -r or --remove remove everything except conffiles. This may avoid having to reconfigure the pack age if it is reinstalled later. (Conffiles are configuration files that are listed in the DEBIAN/conffiles control file). -P or --purge removes everything, including conffiles. If -a or --pending is given instead of a package name, then all packages unpacked, but marked to be removed or purged in file /var/lib/dpkg/status, are removed or purged, respectively. Note: some configuration files might be unknown to dpkg because they are created and handled separately through the configuration scripts. In that case, dpkg won't remove them by itself, but the package's postrm script (which is called by dpkg), has to take care of their removal during purge. Of course, this only applies to files in system directories, not configuration files written to individual users' home directories.