Use el siguiente código para borrar el formulario Clonado:
<script src="http://code.jquery.com/jquery-1.11.3.min.js"></script>
<script>
var i = 0;
var original = document.getElementById('duplicater');
function duplicate(){
var clone = original.cloneNode(true); // "deep" clone
i = ++i;
clone.id = "duplicetor"+ i; // there can only be one element with an ID
original.parentNode.appendChild(clone);
clearCloneForm(clone.id);
}
function clearCloneForm(id){
var divId = '#'+id;
$(divId).find("input[type^='text'], input[type^='date']").each(function() {
$(this).val('');
});
}
</script>