So my grandmother told me before they had hair conditioner in the islands (grew up in Cuba) they used beer on their hair and laid out in the sun. She claims the 'froth' is packed with rich nutrients. I am not sure whether she made this up so I would pour it on my hair instead of drinking it. Anyone else ever heard of beer as a conditioner?...
I have heard and seen beer shampoo, both as a home-remedy and a commercial product.
Here is an article about beer shampoo. http://lifehacker.com/5908809/shampoo-your-hair-with-beer-for-a-silky-soft-shine
There are certainly a good few beer based shampoos available. Even Carlsberg make a beer shampoo/conditioner. I've no idea whether it's "probably the best shampoo in the world'.