I've tried that a few times. It helps. Do let it sit for a while, 30 minutes or so to let it work. However, for a really slow stubborn drain it didn't help enough. We used some draino and a plunger and then some super intense foaming draino to clean off the sides. I was hoping that if we cleaned out the pipe really well it wouldn't build up so quickly and I would be able to use baking soda to keep it clean or at the first sign of slowness. So far so good.