Red Plum listed a new coupon for $1.50 off any Breathe Right 12 ct or smaller!
Walgreens has the travel size (2 ct) package for only $0.99, making these FREE!
Yes you can use a coupon that is more than the cost of the item, per the Walgreens coupon policy....
* The coupon amount must be reduced if it exceeds the value of the item after other discounts or coupons are applied. (For example, a $5.00 coupon for a $4.99 item will result in a $4.99 coupon value).