Naughty Word Catcher

Hi all, Ive just been asked whether I can do the following task..... When a block of text is submitted via a web form, for it to be checked for offensive words, and rejected if there is. So I put my brain hard to work and came up with a possibly solution. I know this method should work but im wondering if I should tackle it a different way. This is just a rough, typed-off-the-top-of-my-head to show the method rather than correct code. The idea was to have a list of offensive words or phrases in a MySQL database, and the script would take the block of text, and do the following $query="select naughty_words from prude_list"; $result=mysql_query($query); while ($loop=mysql_fetch_array($result)) {

    $naughty_word_checker = stristr("$block_of_text","$loop[naughty_words]");
    if ($naughty_word_checker) {
        header("Location: error.php?reason=prudes_wont_like_it");
    } else {
        header("Location: insert_stuff.php?comment=$block_of_text");
    }

} or is there a better, more efficient way of doing it. Im pretty sure the concept of above will work because if there is a match, stristr() should return text, otherwise it shouldnt return anything (or if im wrong, a little fine tuning will sort that out). Thanks Chris