Yes I think so, what about this.
Create a new database column called something like NoStock which had a default value of 1
Then the recordset which currently has only a WHERE ProductLive=1 statement would also need to allow products to be displayed which had a ProductLive value of 0 but a NoStock value of 0
Then the client would change the NoStock value from 1 to 0 for only the products it wanted to be displayed with an "out of stock" message in place of the "Add to Cart" button by using the if statement you gave earlier for the button but incorporating the NoStock column instead of the ProductLive column.
So it would be
<?php if($row_recordsetName['NoStock'] != 0) { ?>
[add to cart button code]
<?php } else { ?>
This product is out of stock
<?php } ?>
Is this a working solution? If so how do I write the statements for the recordset starting with WHERE ProductLive =1