Hey guys I was just wondering if anyone could help me solve my little basement mystery, I have a hole in the floor that's about 10 inches by 10 inches which is filled with gravel or flashing, about half a foot deep and there is a drain in the middle sticking up about 3 inches, just last month I decided to clean all the drains with some drain cleaner but this drain wouldn't take the water and cleaner down so I tried to unclog it but that was a bad choice because it's connected to the upstairs or main floor kitchen sink, so anything that I unblocked is letting the water from the sink upstairs come up this drain in the basement floor. As a temporary fix I bought a temporary plug and I also want to know what I could use to get rid of the smell because I've tried putting bleach but the flashing just stinks thanks guys!