That's a great way to do it. Might want to make sure its output is back an array again. Now you're only showing the last unique value.
Try this:
$arrDuplicate = array ("","",1,3,"",5);
foreach (array_unique($arrDuplicate) as $v){
if($v != "") { $arrRemoved[] = $v; }
}
print_r ($arrRemoved);