Comment 7 for bug 250696

Turning off xdg-user-dirs-gtk-update and gnome-at-visual left five zombie processes:

jockey-gtk
pactl
gnome-login-sou
gnome-power-man
gnome-volume-ma

Turning off all options indeed had zero zombies, albeit with a crippled desktop. I ran each command manually, one by one, but they all came up with no zombies.

I then tried mixing it up a bit doing different combinations. In the end I tried the top half of the list, and then the bottom half. Both times I had at least a few zombies, which rules out the cause being an individual one of those processes.