German quality testing agency Stiftung Warentest reviewed 20 laundry stain removers and 3 ultrasonic stain removers. Experts emphasize that the decontamination ability of stain remover is limited, and everyone needs to pay attention when purchasing! Daily laundry detergent/detergent is enough, no need to use additional stain remover. If you want to buy, it is recommended to choose the two "Gut" stain removers.