So I installed icewm and "removed" xfce4. I tried both purge and
autoremove, but there's still a bunch of xcfe4 stuff hanging around. I
could remove them one at a time, but there has got to be better way...
I hope?

root@dev3:~# apt list --installed | grep xfce | sed "s/\/.*//"

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

libxfce4panel-2.0-4
libxfce4ui-2-0
libxfce4ui-common
libxfce4util-bin
libxfce4util-common
libxfce4util7
xfce4-battery-plugin
xfce4-clipman-plugin
xfce4-clipman
xfce4-cpufreq-plugin
xfce4-cpugraph-plugin
xfce4-dict
xfce4-diskperf-plugin
xfce4-fsguard-plugin
xfce4-genmon-plugin
xfce4-goodies
xfce4-helpers
xfce4-mailwatch-plugin
xfce4-netload-plugin
xfce4-notifyd
xfce4-places-plugin
xfce4-power-manager-data
xfce4-power-manager-plugins
xfce4-power-manager
xfce4-screenshooter
xfce4-sensors-plugin
xfce4-session
xfce4-settings
xfce4-smartbookmark-plugin
xfce4-systemload-plugin
xfce4-taskmanager
xfce4-terminal
xfce4-timer-plugin
xfce4-verve-plugin
xfce4-wavelan-plugin
xfce4-weather-plugin
xfce4-whiskermenu-plugin
xfce4-xkb-plugin

--
Walter Dnes <waltdnes@???>
There are 2 types of people in this world
1) Those who can extrapolate from incomplete data