We'll create fresh WordPress site with MslsSelect installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Most people are likely to use some lines of PHP or the widget provided by the Multisite Language Switcher to integrate the links to the translations in their blogs.
But if you look for an easy way to change the output of the Multisite Language Switcher as an HTML select with some JavaScript that forwards the visitor automatically after selecting an option then give MslsSelect a try.