Onions against flu

In Austria, the flu is currently on the way. In conversation with my neighbor, we also came to talk about this topic, and she had a tip from her grandmother:

In each room of the apartment or in the office, an unpeeled onion is placed on a plate and placed so that it does not immediately catch the eye. Allegedly, the onion absorbs all harmful bacteria.
I thought: it's worth a try. If it does not help, it does not hurt anyone and it's not expensive, because you always have onions in the house.

That was 2 weeks ago and so far no one in my family has become ill. I do not know if this is due to the onion or just believing that it helps? But I do not really care, the main thing, the flu spare us!

In this sense - stay healthy!