This question already has an answer here:
I am wondering if there is a User Friendly (GUI) way to enable/disable the Guest Session.
If not, is there a way to allow logged in users to create Guest Sessions, but not from the login screen.
I am aware of this:
If you're using the default LightDM in Ubuntu 11.10, edit /etc/lightdm/lightdm.conf so that it looks like this:
Will this suit my fallback?