Yeah, I was searching on Amazon and came across it. It had a lot of good reviews so I bought the shampoo and conditioner combo, although I haven't been using the conditioner. The shampoo bottle is a PITA because you have to put channel locks or pliers on the nut and turn it to release the dispenser. My bottle is only about half gone, so it should last at least six months, possibly more.
I think they'd prefer you use it every day, but whatever you're comfortable with.