The floss is under $1 at Walmart and Target, so 100% FREE after the coupon. Also, keep in mind that this coupon has a limit of one coupon per person, and no more than 4 coupons of any kind for the same product in the same transaction.
There also happens to be a Catalina offer for Reach floss:
So, with them costing about $1 each, and if you are shopping with 3 other people, you can make $3! If you are shopping with only 1 additional person, that use of the $1/1 coupons, and one of the $1/2 printable coupons, you would make $2. If you are shopping by yourself, use 2 of the $1/2 printable coupons, and you would make $1! Some of the participating stores are listed above. I'm pretty sure they're about $1.07 at Fred Meyer.