Hi, everyone! I've been shampoo-free for about three years, I think. I have long-ish wavy-to-curly hair, fine-textured but lots of it so it's been described as "thick" most of my life. I actually don't even rinse it with water very often. Every month or two or whenever it seems to need it, I do, and then usually I use baking soda (with rosemary essential oil) scrubbed in and then herbal apple cider vinegar in the rinse (I steep rosemary, juniper berries, and mugwort in the vinegar and I also use this vinegar to soak a clean washcloth and place on my forehead to help relieve headaches). Lately that's left it a little too dry afterwards, and prone to static, so I think I'll stop using at least the baking soda and will likely stop using both even though I really like my herbal vinegar (leaves my hair smelling great). We exclusively use filtered raincatch for our water.
When I first started to decrease the frequency of washing with shampoo, and then stopped using shampoo altogether, my hair would definitely get greasy. But now it takes it at least a month to get greasy at all. So for those who've asked about how to moderate greasy hair, I would say just give it some time. Maybe stock up on cotton hair wraps (bandanas or whatever you like) to wear over a bun until things settle down. I still wear these to keep blowing dust and grease and things out of my hair when doing dirty work or riding a motorcycle or just being out for any length of time in the spring windy season.
Anyway, the main thing I do to clean my hair and keep it healthy is comb and brush it for a good long time once a day. I use a very wide-tooth comb (what they sell as a "shower comb") first because I couldn't get it through the tangles without a ton of damage otherwise, and once it's thoroughly detangled, I use a brush in sections so that I make sure to get all the way to the scalp. This removes dust and dirt and distributes the scalp oil all the way to the ends. For years I've used a nice wooden-handled brush with soft "natural-feeling" bristles, but I actually don't know whether they're boar bristles or plastic, and I sort of suspect the latter.
I just finally got myself a brush that I'm sure has good long boar bristles, and I'm excited to try it. Best of all, it didn't cost an arm and a leg, the avoidance of which had kept me from investing for this long. What I got was a Calcutta boar bristle brush with a pear wood handle from Desert Breeze Distributing, and because I don't care if there's an "odd grain pattern or flaw in the wood handle" -- in fact, I'd prefer it -- I got it for a discount, and threw in a cleaning kit, too. All three wooden-handled items (the brush, a cleaning rake, and a cleaning brush) appear to be very high quality. I have no affiliation with the company, but I'm a repeat customer, as I've also bought a very nice wool pad from them that I use for needle felting. So I'd recommend them highly. Here's a link to the discounted brushes
We don't use soap, either, except on our hands and if there's some kind of actual grease or filth on us like if we've been changing the oil or otherwise working on vehicles or have spilled while cooking or have turned the poop compost or something. We've tried making our own simple coconut oil soap to use for that and dishes, but so far it hasn't worked -- can't get a trace, maybe because we're stubborn about using lye we make from the hardwood ash from our stove rather than buying sodium lye. So we use a simple shea butter soap for our hands and carefully-vetted liquid detergents for dishes and laundry that won't put too much sodium into our greywater. We do use just diluted potash lye for laundry sometimes, but I don't feel it gets clothes as clean (my partner swears by it).
My skin has been healthier these last few years since making this change than ever in my life before. Using one of those salt crystal deodorants is helpful at preventing armpit odor, although that also is reduced since I gave up coffee again last year. For dry skin I use various herbal oils I make with olive oil, and I use a lot of creosote salve (creosote herbal olive oil and beeswax) for cuts, scrapes, insect bites/stings, and especially any kind of early skin damage from the sun. (I'm bad about remembering to put on zinc sunscreen, and it took me a while to find a wide-brimmed hat I really like that does a great job now of blocking sun from my face.)
I will say that, doing this, it becomes much clearer what we each individually really smell like, without scented products that strip our natural oils, and these smells vary a lot from person to person. Luckily my partner and I both like each other's smells. Except when it's really hot or we've been working especially hard, these aren't strong smells, and then we bathe, eh? My partner likes the smell of my hair so much he actually gets a little miffed when I wash it and it smells more like herbs for a few days. But I can see problems arising if you start doing this when you're already in an established relationship and then you don't end up liking each other's smells... Check in with each other! It might reveal some interesting things.