I have used your code in the following format:
CultureInfo culture = CultureInfo.GetCultureInfo(
System.Threading.Thread.CurrentThread.CurrentUICulture = culture;
However, links generated by Sitefinity that look like this:
When clicked on, redirect to:
on a second postback reveals that the CurrentUICulture has reverted back to "en", rather than "ja" as per my example. It appears Sitefinity is reverting the Culture change to its original "en" culture.
There must be more code to change sitefinity's handling of the language than what you've already mentioned?