All that does is tell Windows Installer which 'codepage' to use to display the strings. It does not switch to a different set of strings.

To retranslate strings, you need to go to \Visual Studio \Common7\tools\deployment\vsddialogs.

Copy the 1033 folder to something like 1025. Then open each .WID and .WIM file and edit all the display text...

the two places you are most likely to find them are in the Control table and Property table. It's kind of tricky, and lots of dialogs and controls, etc... it's a lot of work