No. Way.
Three non-americans tell me to not wash my hair for six weeks and it will be lovely?
Not falling for it.
Seriously though, I'm dubious to the science behind this.
And I'll never try it. I kind of like my hair. And the hippies I've known are all dreddy and stuff and NO you don't use shampoo on it because oil is hidden under the mats and is needed and must be allowed to seep slowly into the outer tangles.
The older hippies I've known just have, plain and simple, greasy hair. Not all hippies. Many hippies wash. Just not the dirty ones.
I loves you guys, but I'm not believing this particular chain of words-of-mouth.
In any event, when the apocalypse comes, I trust you will all send me your shampoo. I'll send you food, you send me lilac-scented loveliness.