For an easy way to save on Arm & Hammer detergent, check out your local Rite Aid store. This week, Arm & Hammer detergent and scent boosters are buy one get one free. Download the store app and clip a coupon to pay $3.15 for Arm & Hammer detergent. Or, just use the sale to pay $3 each for Arm & Hammer Scentsations. To get this deal, sign up for a Wellness+ account if you haven’t already. Keep in mind that this sale is available in stores only.