Amazon Prime Day offers a discounted price on Calgon 4-in-1 Washing Machine Cleaner and Water Softener Tablets, which help remove limescale, residue dirt, rust, and odors while cleaning your machine. Shoppers rave about the effectiveness of these tablets in extending the life of their washing machines and eliminating unpleasant smells. However, some reviewers note issues with the tablets dissolving completely and potential damage during shipping.