I use this stuff for my WA GBB's
http://www.futureshop.ca/catalog/pro...8&catid=10652#
I dunno if it's tetraflouro-whatever or diflouro-whatever, but I'm going tomorrow to pick up that MG stuff you guys mentioned, it seems really good from what I've read online and there's a retailer that his it literally around the corner from my house!