Wal-Mart: Free Original Reach Floss
Original Reach Floss is only $0.99 at many Wal-Mart stores. Use the $1/1 or $2/1 Listerine/Reach products coupon here to get it for free (different zip codes show different values of coupons).
In addition, if your zip code is showing the $2/1 Listerine/Reach coupons here, be sure to print them--and print extras if you can! These will be on sale 3 for $9 at Walgreens the last week in June and will produce a $3 Register Reward. So, after three $2/1 coupons and the Register Reward, you'll get all three products free!