Vaginal douching?

So I was just listening to a podcast and the hosts were talking about vaginal douching. I'd never heard of it before, so Googled it and fell down a rabbit hole of douching and discovered between 20-40% of females in the US do it. I'm from the UK and managed to get to the age of 24 having never heard of it before. I'm just intrigued to find out how many people do this? It seems a bit weird to me because your vagina naturally cleans itself out and it's a v delicate system, so to squirt vinegar/water mix up there seems a bit unnecessary. But I'm interested to find out why people do it! Do any of you do this?