Found this on another forum,smoke grenades designed for paintball and airsoft. I imagine we would be allowed to use these as its cool burning so no flames. The problem is they charge 22.50 on top of shipping as its considered hazmat.
http://www.sportsmoke.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=17&category_id=6&option=com_virtuemart&Itemid=94
http://www.sportsmoke.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=17&category_id=6&option=com_virtuemart&Itemid=94