facebook oauth can't logout user who doesn't accept permissions

Question

I have a facebook application that runs in a kiosk at my restaurant, it allows users to check-in. That works great, if they log in and accept the permissions needed, it then lets them logout when they are done without the slightest problem.

If however they don't accept the permissions no method of logging them out will work. I have tried everything I can think of and every post I could find on stackoverflow.

How can I log the customer out if auth doesn't have the permission from the user?

I have reported this to facebook using the bug report, they have stated that they are looking into it. Just hope one of the geniuses on here had an idea.