Q: I have a hard time getting my hair to feel really clean. What's the best way to cut through hair-product buildup?
A: The standard DIY/holistic answer is to soak your hair in apple cider vinegar. Uhm, no thanks. A much less stinky solution is Frederic Fekkai's Apple Cider Clarifying shampoo. It contains apple cider vinegar, but also vitamins A and E and good-smelling ingredients like rosemary, verbena, and sage. Its consistency is more watery (less soapy-sudsy) than most shampoos; think of it as a rinsing treatment to use once or twice a month, or whenever you feel like your scalp is feeling itchy from too much product buildup. It doesn't overstrip hair but definitely clears out the leftover styling oils, dry shampoos, and volumizer goop.
In cold weather, people often report that their scalp feels especially irritated — probably owing to a combination of the product buildup and dry skin. Philip B.'s Anti-Flake Relief Shampoo contains .525 percent coal tar (yup, that would be the same stuff that kills head lice) and zinc to help cut through product residue and restore the pH balance in your skin. I use this about once a month during the winter for maintenance measures, even if I don't have product residue, just dry scalp. Unfortunately, because of the coal tar, it smells a little like farts (sorry!), but it will leave your hair shiny, itch-free, and clear of gunk.