women should stock up on shampoo. Silly, but in the PBS series 1900s house, it was the lack of shampoo that bothered the women the most. People in that era only washed their hair once a month with an egg white mixture. Yuck!
That won’t be a problem, because you aren’t going to be able to afford the eggs anyway, assuming they will be available to buy.
You’re going to have to switch to something that can sit on a shelf for months before opening, like beer.
If corn meal isn't available, saw dust is said to work well . (I've never tried it.) Others have tried something called a 'Mexican shampoo' : Take a coarse terrycloth wash rag or small towel (NOT a fine terry cloth or one that has been laundered with fabric softener ) and use it to 'pull' the sebum off the scalp and down the length of the hair , one section at a time.
I don't recommend the dry shampoos in a can :I find they always leave a white talc-y residue on the hair. But a corn meal rub/comb, followed by a plain water rinse works well.
I still use store shampoo, but only 2 or 3 times a week, and only if it's paraben/SLS/petroleum free. Since I started this regime , my hair looks thicker and healthier. When I used ordinary shampoo every day, it would look good for maybe a few hours, then it would look very greasy and lank, because I had strpped out the sebum, causing the glands to work overtime to put the sebum BACK on my scalp, the glands would over do it,causing my hair to look very thin and lank, making me feel I HAD to shampoo it daily to give it any body at all, stripping the oils and out and-well, you get the idea. Now I run water through it daily when I shower, use the cornmeal/corn starch rub when needed, a baking soda mix maybe once a month (it's harsh) , and using the organic shampoo maybe 1-3 times a week. My hair will never be luxuriant (it's fine textured, and not overly thick) but it LOOKS thicker than it ever did when I was shampooing it daily, and it has way more body and 'lift' at the scalp, instead or just lying limp and flat.
Not everyone agrees with the idea that SLS/Paraban/petroleum shampoos are bad or that using them daily is counter productive, and that's fine : I just thought my experience with dry shampoos and shampoo substitutes might be helpful for dire/apocalyptic circumstances when store bought shampoos might not be available. (Asssuming under such circumstances we'll even *care* about how our hair looks-! :-D )
Vinegar works too.
The cleanest and shiniest my hair has ever been was when I would scrub my scalp with baking soda, then rinse with lemon juice. I stopped doing it because it got to be a hassle, I’d forget to grab those bottles until I was already in the shower.
Also, if you grate some lye soap and mix it with a little milk or water, it makes a decent shampoo.