As seen in Women's Health...
... and available online at Beautyhabit: https://www.beautyhabit.com/products/christophe-robin-purifying-hair-finish-lotion-with-sage-vinegar
Exactly How to Keep Your Long Hair from Looking Mangy "Hair vinegar" is a thing you need to know about.
"New products offer the benefits with a more sophisticated scent - Christophe Robin Purifying Hair Finish Lotion, for instance, uses a not-at-all-sour-smelling sage vinegar as its acidic agent. Once a week, spritz it onto dry hair from roots to tips and run your fingers through strands to distribute."