So, it seems you can't fix this just by running chlorine or whatever down the drain and hoping.
Turns out the reason your kitchen sink stinks is because you have years worth of grease, hair and other shit stuck in your drain.
Time to take it apart and clean it....

After reassembly, fill the sink halfway, release it, and check underneath with dry paper towel for leaks.
| References | URL |
|---|---|
| Have you ever cleaned your kitchen sink drain? | https://www.tiktok.com/@ken.c.long/video/7377386350112197893 |