It's no use. Any exercise aimed at local slimming is useless. Local muscle gain is possible, while local fat loss is basically impossible. Unless you rely on drugs such as stovepipe cream to reduce your stomach, either massage with essential oil or use drugs such as burning grease (the latter is not necessarily useful). If you exercise, even if you exercise locally, you will lose your whole body
Unless you want to gain muscle, you can consider tearing abdominal muscles, which can also reduce fat but also reduce the whole body. Is anaerobic exercise the main function or muscle gain?
What kind of abdominal massager is a waste of money?