можно удалить вручную:
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<form>
<input class="clear" type="hidden" value="234" default-value="234111">
<input class="clear" type="text" value="2345" default-value="2345">
<textarea class="clear" default-value="25">25</textarea>
<input type="button" value="reset">
</form>
<script type="text/javascript" src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
<script type="text/javascript">
$('form input:button').click(function()
{
$('form .clear').each(function(index, elem)
{
$(elem).val($(elem).attr('default-value'));
});
});
</script>
</body>
</html>