You know, my mother used to do this, clipping the cents-off coupons from the Wednesday newspapers and the Sunday supplements--but no such thing as "double coupon offers" in the Sandhills when I was growing up--but it always seemed to me what she "saved" in money she spent a great deal more in time.
Yeah, sure, it was nice to save (then) $4.57 off total purchases of circa $44.89, but to get that "savings" cost her a oouple, maybe three, hours at a time.
When I first went away to college, I tried the stunt myself, but it was never worth it. One might as well purchase what he wishes to purchase, or needs to purchase, and to Hades with whether or not one has the "cent-off" coupons.
Another store TRIPLED coupons about twice a year. No problem buying like $400 worth of groceries for like 50 bucks that way. It took some effort to sort the coupons scientically but well worth the time spent.