remember, if you are flying along and your outflow valve is almost completely closed in normal ops, it won't help that much when you blow a window.
planes develop leaks along their lives and I remember one flight attendant telling me how they proped a piece of soap in the lavatory basin drain...this would suck all the foul smelling odors out of the lavatory...but affected our pressurization especially in a reduced power descent.
but if your outflow valve is fully open and you lose a window, the size is comparable take a look at the outflow valve(s) the next walk around...about the size of a window.
not that it will be comfortable in the cabin