René Furterer Naturia Dry Shampoo
"Excessive shampooing leads to dehydration of both the hair and scalp. Not to mention, there are days when it's just too cold to go outdoors with a soaking-wet head. So I rely on this product to cleanse and refresh my hair; I simply spray it in, then brush it out. Since you get the cleansing action without having to use water, it's ideal with extensions. The formula has clay and silica powder to absorb excess oil, plus essential oils like caraway, basil, and peppermint keep my scalp clean."
$24 for 3.2 oz; sephora.com