formit hook is php - running on the server
jquery - running in the browser
php code on the server cannot not 'call' js in the browser
a possible solution would be for the the formit hook to add the jquery code to the page as needed - the jquery code would would run once the page was loaded.
But why do you need the jquery? It seems to me that if you are running a snippet (php to process the from submission) you might as well do the content refresh with php code at the same time rather than create a page and then run some js code and then load (with presumably ajax) the refreshed content (which is going to involve php on the server side).