I found some super Listerine deals for you over at Amazon. There are some nice high-value coupons on some product pages that can be combined with sales and subscription discounts. Check out these nice deals I found:
Listerine Cool Mint Antiseptic Mouthwash 1.5L – only $5.69 with sale, subscription and coupon (reg. $10.70!)
Listerine Total Care Anticavity Fluoride Mouthwash 1L – only $5.32 with subscription and coupon!
Listerine Cool Mint Antiseptic Mouthwash 1L – only $4.34 with subscription and coupon (note the 1.5L bottle above is a better price per ounce!)
Listerine Freshburst Antiseptic Mouthwash 1L 2-pack – only $8.68 ($4.34/bottle) with subscription and BIG coupon!