popping to rootview controller

If I have a navigation controller with the following structure:

nav -> login -> slideout -> three view controllers

from one of my view controllers in the slideout, I want to pop to the root view controller or the login controller. Is this not possible? From the view controller, a user hits a logout button and then they should pop back to the login screen:

viewcontrollerInSlideout *my_vc = [self.navigationController.viewControllers objectAtIndex:0];
[self.navigationController popToViewController:my_vc animated:YES];