There is documentation for test users in the Facebook Developer online documentation but how do you delete actual users where the application doesn\'t show in their app list
You seek for application de-authorization:
You can de-authorize an application or revoke a specific extended permissions on behalf of a user by issuing an HTTP DELETE request to PROFILE_ID/permissions with a user access_token for that app.
permission - The permission you wish to revoke. If you don't specify a permission then this will de-authorize the application completely.
To achieve this issue request to:
https://graph.facebook.com/me/permissions?method=delete&access_token=...
Once application de-authorized it will not appear in the list of user's applications.