Trust me, I was skeptical too. A rock of shampoo, eh? Sounds about as effective as a steel wool pad as conditioner. But after trying it multiple times at an adult sleep over -- don't judge -- I slowly became convinced. The stone of shampoo seems to last forever (if you keep it in a dry place after use), and it comes in a variety of scents. I recently picked up cinnamon and clove. But most importantly, it's pretty damn effective. The shampoo itself lathers nicely (sorry to sound like a Prell commercial... wait, do they still make that?) and at about $10 a rock, it's a better deal than it appears. You can pick this up at Lush's stores or online.