I've read several guides to decarbing that recommend covering in foil or using a pan with a lid when you put it in the oven. Supposedly it's to help trap the vapor for any that gets hot enough to vaporize and then if you let it cool before opening it can settle back down. Sounds a little fishy to me, as I don't see vapor antomatically reattaching itself as it cools down like that...but that's a different debate. Anyhow...if that is a good procedure, than using a sous vide bag setup would be taking that to a whole nother, really really sealed level. and I don't see a reason not too.