Waste water from kitchen can include a lot of putrecsibles (small pieces of food, other organics) or any kind of tiny litte garbage that end up being washed away.
Catch whatever you can... and it will make your waste water probably much cleaner.
I found this at local Japanese grocery store. Since the package is in English, it might have already been marketed outside Japan, but I have no idea how much penetration it's earned.
The product is named "Aqua Top" and it says "water tool". Well....I don't know what it means, but.....
By the way, this product had Japanese eco-label on it.