it is a way to keep your hair free of burrs, splinters, dirt and dust.
This right here. Realistically, Reynir's dangling braid would have been catching on branches and collecting allll manner of forest nonsense in Saimaa. With no showers for weeks.
The other comic I mentioned, with the black smith - he at least lived in a small city and a stone house so the most it was likely to catch on was when his friend intentionally yanked it (which happened). Farms and forests? It'd be secured to his head.
And as for cleaning long hair in a freezing winter: one of my aunts, who had long, very fine hair that came to her knees when she loosed it used to make orris root powder and if she wanted to clean her hair when it was cold and snowy she used to rub the powder through her hair, let it sit for half an hour, then brush it out. This process left it clean and smelling delicious.
The powder is basically dry shampoo - which you can get cans that are basically starch with, i believe, aerosol but more people are remembering to just put various powders on like this.
Mmm gosh the discussion of hair cleanliness, I only just remembered how many people wash their hair fairly often. So to them this might seem particularly baffling. I stopped using shampoo in 2014 and my partner never has, conditioner only. We also have curly hair so it takes a lot of special attention.
Brushing alone moves a lot of the oils through the hair and keeps the scalp fairly clean. And hair that long, you *need* those oils to get as far through it as possible. It'd get pretty dry and brittle if it was wet too often.
Reynir doesn't necessarily
ever need to shampoo/soap his hair, and wetting it doesn't necessarily need to happen more than once a week or so. Less if he's got access to a starch powder (like the orris root mentioned). When he has the luxury, so not in the silent world, he may need to work oil into the tips at minimum.
How often it needs to be brushed depends on how oily his scalp is, and if you aren't overwashing that tends to settle down.
And Emil - he has short, straight hair so that tends to be lower care needs. Yes it's not unlikely that with a comb/brush and the rare times they wash his hair would stay lovely looking.
My 5yo has hair a lot like Emil and honestly we wrestle her into a bath less than once a month. Her hair is gorgeous as long as she lets me brush it. And honestly is somewhat similar to Emil's but with curls (most of it looks straight as it's chin length, but the hair framing her face curls) I know kids have better hair than adults but still - those genetically lucky people have hair that can be quite low maintenance and still look good.
Lucky bastards.
(For more info you can look up the "no shampoo" movement. It's not for everyone, but it also includes a lot of natural hair care that may be similar to what SSSS-verse uses so is interesting.
Also, Tuuri is the smartest of all for just shaving the damn stuff off!)
Nowadays my plaits come to a little below my shoulders. My hair grows slowly, and although I have been growing it all my life I have twice lost it to chemotherapy and twice had it shaved or severely cut back for surgery on head injuries. My avatar picture is a good cartoon of what I actually look like, though Haiz made it a bit prettier than I am, and people seeing it have certainly recognised me from it.
You sound like you've been through a lot. And I suspect are a bit harsh on your looks, too, especially if people can recognize you from the art.