According to a viral video, onions can be used to absorb germs in your house. But of course, that would put a lot of people out of business, so there are no official studies to back it up. Does this mean they don't work? Nope. It means you need to be skeptical. Research studies mean nothing. They're a scam, like anything else regulated by the government. Cut up red onions and put them around your house, replacing every two days. No, it won't make your house smell like onions.. not for long at least. I've done it, and the smell isn't overpowering. Don't touch the onions, they're full of germs. So be careful when you dispose of them.