I must have karma with the sewer. Because in the last two years, I think I've researched every company in Toronto that provides plumbing services. But none of them could solve my problem. Every week or two my drains clogged. Until a friend suggested calling POM Plumbing. They are the only ones who did a good job https://pomplumbing.ca/snaking-and-power-wash-of-kitchen-stacks-and-clogged-drains/. I don’t know what exactly they did, but for more than a month I didn’t apply anywhere. But if something happens, I will call them.