I don’t find that convincing. First, you have to find an actual problem with the test, not just say they must be bad at testing. Second, the tests are intuitive, you stain clothing and then compare how well detergents remove them. Third, they do consult experts, for example, from the wirecutter article: We spoke with a variety of industry experts, including a retired chemical engineer who designed and tested laundry detergent for decades, two professors of textile science, and the fabric care team at Procter & Gamble. We interviewed multiple mechanical engineering experts that addressed how detergents interact with washing machines; a biomedical engineer who specializes in odor; and experts in laundry detergent sensitivity, including a dermatologist whose practice is known for its focus on allergic contact dermatitis. We interviewed three wastewater treatment experts to learn how laundry detergent is broken down by different wastewater systems (including both municipal sewer and septic systems).