I think the “save session” option on the logout screen in Xfce is dorky. So I found a way to remove it. Here are the steps:
sudo mkdir /etc/xdg/xfce4/kiosk
sudo vim /etc/xdg/xfce4/kiosk/kioskrc
Add these lines:
[xfce4-session]
SaveSession=NONE
Done. You can also do this to clear out any previously-saved sessions:
rm -r ~/.cache/sessions/*