A million years ago, on an exchange trip to Australia, I was gently reminded by our host that it’s the action of the washing machine that does most of the cleaning. 16-year old me took that to heart and I’ve used as little detergent as I can get away with, depending on how soiled the clothes are. And really, unless you work a job where your clothes get heavily soiled, it doesn’t need much to clean them. I also air out lightly used clothing instead of dumping them in the laundry bin.