I think the modern hygiene standards are unreasonably excessive. People look at you weird if you shower any less than once a day. But I think that you can go far longer without showering. It's only once you start to smell bad that showers are really necessary, it is the nature's way of saying hey stinky time to wash off that dirt off of you! And you don't start to smell until quite some time, longer during cold weather. So I think that showering once a week for example is perfectly fine. And during winter I can take one every 3 weeks and it's also fine.