Just tried dry shampoo for the first time yesterday actually. I'm a male in my mid 40s who started growing my hair out about 2 years ago and it's to my shoulder blades now.

I have electric heat, hard water, and somewhat dryish hair so I try to use shampoo just twice a week if I can help it, so as to strip a minimum amount of oil from my hair and keep it from frizzing all over. It works pretty well, but by day 3 it is pretty heavy and there are spots that look greasy and don't feel great or look good.

I've been sick as hell this week and have been falling asleep at random times. So I woke up yesterday after falling asleep before showering. I had time to shower, but having long thick hair takes a long time to dry, and part of my work is outside, and since it's around freezing here, I didn't want to have a wet and heavy head of hair outside while I'm already sick.

So I looked in the wife's rack of hair stuff and saw dry shampoo. I said if this isn't what this stuff is made for, what is? And I shot my head all over with it. My hair was still heavy and not the best feeling, but man, did it look a ton better than it did before using the dry shampoo! In some ways it even looked better, as the heavier hair can style better, but it usually isn't visually appealing, but with the excess oil absorbed, now it did look good.

It got me through the day looking kempt and professional, and while I fell asleep immediately when I got home again and still haven't washed it, if I had to leave home this second, it'd still be passable. Again, it doesn't feel like the best hair ever, but it will fool everyone else if need be.

So while teens may overuse it and it is no excuse for a shower, I don't see how the owner of the hair would be fooled into thinking it's clean instead of just dry and manageable. If the high school girls have gym or sports, I bet they would have some of this so they can freshen up after activities and to not look or feel gross while being constantly judged by other teens.

As a guy who had quarter inch hair for most his life, none of this ever made sense to me either, but now trying to learn how to care for long hair, it is such a complex thing! You've got to learn your body chemistry by testing all these things so you know how to keep your hair looking nice when it's super hot out or humid or windy. Hair snags hurt, and frizz is a bitch if you're trying to look presentable. So until you live it, try not to get too judgy. Using this stuff isn't fun, but for people that want to have long hair, these products exist because people need and want them to make hair care better for themselves.