Help creating a censor “allow” list!

Okay, so I currently have a censor installed. Here is the current code:

<?php
/*
*	Plugin Name: Censor
*    	Plugin URI:
*   	Description: Filters offencive language.
* 	Author:
* 	Author URI:
* 	Version: 1.0
*
*
*	This program is free software; you can redistribute it and/or modify
*	it under the terms of the GNU General Public License as published by
*	the Free Software Foundation; either version 2 of the License, or
*	(at your option) any later version.
*
*	This program is distributed in the hope that it will be useful,
*	but WITHOUT ANY WARRANTY; without even the implied warranty of
*	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*	GNU General Public License for more details.
*
*	You should have received a copy of the GNU General Public License
*	along with this program; if not, write to the Free Software
*	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

function profanity_comment_filter($content) {

// Add more words below, follow the structure that you already see, and make sure to increment the number.

$patterns[0] = 'fuck';
$patterns[1] = 'shit';
$patterns[2] = 'bitch';
$patterns[3] = 'bastered';
$patterns[4] = 'ass';
$patterns[5] = 'cock';
$patterns[6] = 'cunt';
$patterns[7] = 'a$$';
$patterns[8] = '@s$';
$patterns[9] = 'fuk';
$patterns[10] = 'a$s';
$patterns[11] = '@$$';
$patterns[12] = 'moron';
$patterns[13] = 'retard';
$patterns[14] = 'hell';
$patterns[15] = 'sex';
$patterns[16] = 'sexual';
$patterns[17] = 'drug';
$patterns[18] = 'crack';
$patterns[19] = 'nicotine';
$patterns[20] = 'marijuana';
$patterns[21] = 'smoke';
$patterns[22] = 'alcohal';
$patterns[23] = 'tobacco';
$patterns[24] = 'hump';
$patterns[25] = 'condum';
$patterns[26] = 'tampon';

$finalremove=$content;
$piece_front="";
$piece_back="";
$piece_replace="[censor]";

    for ($x=0; $x < count($patterns); $x++) {

    $safety=0;

        while(strstr(strtolower($finalremove),strtolower($patterns[$x]))) {
        # find &amp; remove all occurrence

        $safety=$safety+1;
        if ($safety >= 100000) { break; }

        $occ=strpos(strtolower($finalremove),strtolower($patterns[$x]));
        $piece_front=substr($finalremove,0,$occ);
        $piece_back=substr($finalremove,($occ+strlen($patterns[$x])));
        $finalremove=$piece_front . $piece_replace . $piece_back;
        } # while

    }
	return $finalremove;
}
add_filter('comment_text','profanity_comment_filter');
?>

As you can see, I manually enter the curse words to be censored. The problem is, when someone posts something with a bad word inside it, such as “class” it appears on my blog as “cl[censor]”. Is there another code I can add to that file to make a special “always allow” list? Thanks in advance!