PHP code:

function convert_filth($text) {
        $badwords = array('gently caress','poo poo','drat','rear end','rear end in a top hat','oval office', 'loving', 'hosed', 'lovely', 'making GBS threads', 'human being', 'friend of the family');
        foreach($badwords as $badword) $filth_in[] = "/\b{$badword}\b/i";
        $filth_out = array( 'gently caress', 'poo poo', 'drat', 'rear end', 'rear end in a top hat', 'oval office', 'loving', 'hosed', 'lovely', 'making GBS threads', 'human being', 'friend of the family');
        return preg_replace($filth_in, $filth_out, $text);
}