Can anyone please help with ensuring that product content &'s are changed to & ?

This previous thread:
http://www.zen-cart.com/forum/showthread.php?t=19837

worked for earlier versions, but not v1.3.5.

Basically I'm looking at the tpl_products_info_display file:

#83 ish <?php echo stripslashes($products_description); ?>

to add something like:

<?php echo zen_output_string(stripslashes($products_description), array('&' => '&amp;'), false); ?>

Also can this cover document_general files?

Many thanks