 Oh, I have to actually scrub it. I can't just pour some bleach down there? No. No, you definitely need to scrub it, and that's why you probably want to take it apart from underneath the sink cabinet. It's probably going to have a trap, the U-shaped pipe, and it doesn't, by the way. That's the source of your problem, but I'm sure it does. Take that trap apart and then really scrub the inside of that with some oxygenated bleach, and I think that that will kill that bacteria, and then the biogas will go away. Okay. Sounds like a lot of work, but I'll certainly give it a try.