I still don\'t understand how iconv works.
iconv
For instance,
$string = \"Löic & René\"; $output = iconv(\"UTF-8\", \"ISO-8859-1//TRANSL
And did you save your source file in UTF-8 encoding? If not (and I guess you didn't since that will produce the "incomplete multibyte character" error), then try that first.
$clean = iconv('UTF-8', 'ASCII//TRANSLIT', utf8_encode($s));