Restricting access to a single Country

We are adding a sales team in a country and we want to restrict their view to only have access to Customers, Contacts, Quotes, Orders, etc. to only that country.

I thought I might be able to create a new Location for that country and set the employee record to that new location and also set the user's role "Location Restrictions" value to 'own and subordinates only'.  It seemed logical that would provide the desired results.

Unfortunately, the user can still see all customers located in the Subsidiary as well as all other information we wanted to restrict.

Has anyone had success in limiting access in this fashion?  Have you accomplished this in some other way?  I know we can create pre-defined dashboard searches to present the information, but the user could still access the full data set in many different ways.