Reebok offers its Reebok Men's Runner Shoes in several colors (White/Grey/Red pictured) for $39.97. Coupon code "OCT40" drops that to $23.98 and unlocks free shipping. That's tied with our expired mention from four days ago as the lowest price we've seen. (It's the best deal now by $15.) They're available in select sizes from 7 to 13. Deal ends October 21.
If you aren't using any of these three methods for significantly saving on laundry detergent, you are washing money down the drain.