This question is about the plastic "Oven Bags" used to roast various kinds of meat or poultry in. I have some of these made by Reynolds Co., and in the Cooking Guide that came along in the package, it says: "Add 1 TBSP flour to bag. Shake! This helps prevent bag from bursting." This was before you put the rest of the food into the bag. Well, it didn't burst, so I guess that means it worked, but they also had me cut six slits into the bag to let steam escape.
My question is how would the 1 TBSP flour prevent the bag from bursting, and why would it burst anyway, with six slits in it?