WPF - Separate Resource Files "Per Client"

I have a WPF application that will be used by multiple clients. Where clients want a different theme/skin, I am following the approach here - http://www.codeproject.com/KB/WPF/SkinningInWPF.aspx. This is great, but there are also times when client wants windows to contain different text and wording (not necessarily language change only). I have been reading this article for this - http://www.rhyo开发者_运维百科us.com/2010/10/20/using-resources-resx-for-strings-in-a-wpf-application-a-technique-to-prepare-for-localization/.

How should I go about telling the application which resources.resx file to use when it is "client" specific?