Exactly i had the same requirement. But resetting the drop down list by setting simply empty string with jquery won't work. You should also trigger update.
Html:
<select class='chosen-control'>
<option>1<option>
<option>2<option>
<option>3<option>
</select>
Jquery:
$('.chosen-control').val('').trigger('liszt:updated');
sometimes based on the version of chosen control you are using, you may need to use below syntax.
$('.chosen-control').val('').trigger("chosen:updated");
Reference: How to reset Jquery chosen select option