Nothing will happen to a person, without soap and shampoo, people do not die) and the skin, perhaps, will also thank you) hair, however, is unlikely), they may be grateful, but it will look different☺️
About soap, I can say from my own experience - nothing bad will happen, provided that your skin is not oily throughout the body. I use surfactant products (shower gel, soap, etc.) only for places with increased secretion - armpits, feet and groin area, very rarely for the back. I just wash the rest of my body with hot water. It washes away dust well, and sweat is water-soluble. The skin began to dry less, I didn’t get covered with acne, I don’t smell bad :) I will assume that soap / gel is necessary for an overweight, sweaty hairy man, because sweat settles on the hair and you cannot wash it off without a washcloth / surfactant.
As for the scalp, it produces sebum and sweat, which, again, remain on the hair roots and make them dirty and foul smelling (sebum is a breeding ground for bacteria). You cannot easily wash off the smell and dirt from dense hair, it must be washed with special products such as shampoo.
Covoshing is the practice of not washing your hair with shampoo. Over time, after refusing to wash your hair with shampoo, it becomes denser, more elastic and shiny. With the skin, it seems to me, it is the same.
In shampoos, shower gels, washes, not only are full of preservatives, but also all sorts of unnecessary sulfates and other things that further affect the work of the sebaceous glands and internal organs secretion. on which we fall into a kind of dependence.
To summarize. It's worth trying as an experiment, it's interesting. What exactly is worth giving up - antibacterial soap
Nothing will happen.
My child, a preschooler, did not like to wash his hair for a very long time. to such an extent that he could easily pass a month and a half with a "dirty" head. Despite the fact that this is a short haircut, and the child lives in an urban environment where there is not so much dirt, there were no particular consequences, although at some point he still had to wash his hair. As for soap, then again he rarely washes with soap, no more than once a week, although he plays in the bathroom almost daily. Again, he does not have any kind of strong physical activity, all clothes regarding the body change daily, so there are no problems here either. But I think this trick will not work with an adult, you will have to wash with soap and shampoo at least once every three to five days.