Amazon has for Prime Members: 18-Count Swiffer Dusters Multi-Surface Refills (various) for $14.44 - 40% when you 'clip' the coupon on the product page - 5% when you check out via Subscribe & Save = $7.94. Shipping is free.

Thanks to Deal Hunter Rokket for sharing this deal.

Note: You must be logged into your account. Coupons are typically one use per account. You can manage your Subscribe & Save subscription at any time after your order ships. View Subscribe & Save filler items and our current Subscribe & Save Frontpage deals to unlock up to an extra 15% savings when you have 5 or more items in your current monthly subscription.

Available (price after 40% coupon and 5% S&S discount):