Before I start, let me make clear that I have not performed the cleanse itself, though some of its basic tenets I was already adhering to (since a diagnosis a few years back lead to major dietary changes) and others tenets I am adopting based on what I read in this book.
I found Clean easy to read without being overly simplistic or basic. Junger makes great analogies and presents personal experiences that are compelling and concretize the science. Even though I haven't performed the Clean cleanse and though I'm still not sure if I'll go through with it -- maybe at the end of summer when fresh Clean "no-no" foods, like peppers, aren't so readily available -- I wouldn't hesitate to suggest this book to anyone who is curious about food, health, wellbeing and their relationship. In fact, I have already sent copies of it to my mother and my uncle.
To be honest, I am currently very disillusioned with Western medicine, having basically self-diagnosed myself (and having docs go "oh you're right!" upon seeing results for tests I demanded) after upwards of 20 years of illness that saw me dismissed as, at best, someone who wasn't really ill to, at worst, a full-fledged hypochondriac. On the other hand, I'm not ready to jump into alternative medicines because, while Western medicine is the victim of Big Pharma's snake oils, alternative medicines often seem replete with other types of scam artists. "I want to believe" -- remember that line? I need something in between those two worlds. As such, I believe what I read in Clean because, yes, modern, common-sense science does support it (regardless of what headlines Big-Pharma's research may blast), millennia of practice of eastern and alternative medicines support it and my own personal experience supports it.
The things you put in your mouth (or on your skin or, well, other orifices that I'll thank you to keep to yourself) become the building blocks of the cells of your body. Their quality is important. And for some of us with weaker (different?) genetic predispositions, these food or product choices -- choices so many of us make subliminally and without thinking -- have a direct impact on our well being in the short, medium and long terms. Evidently, these things have an under-diagnosed and undervalued impact on the wellbeing of individuals generally deemed as healthy, too. Just because most people feel a certain way doesn't make it the healthy way to feel.
Junger clarified many of the suspicions I already had based on my personal experience and previous readings, and also introduced me to great concepts for which I am thankful, such as the idea that your thoughts can be building blocks for cells as much as food can. (It makes sense if you read the book, even from a Western-medicine point of view -- I won't ruin the punchline for you!)
Speaking of which, my only two negative thoughts when it comes to Clean are as follows:
1. If you read it one page at a time like I did (as opposed to jumping to what you figure are "the good parts"), you may or may not realize that it reads like a giant marketing campaign for this cleanse. In the first chapter, the references to the Clean cleanse are minimal. In every chapter, they increase. By the chapter before Junger explains the actual cleanse, you almost feel like you're in an infomercial. This made me uncomfortable and sometimes distracted me from the actual message because I kept feeling like a scam was afoot. I just really, really, really don't trust any kind of marketing (and I work in PR for a do-gooder cause!).
2. Upon learning that Clean sells its own line of --very expensive-- products, my feelings in #1 were compounded. You can admittedly and most definitely perform this cleanse without all the products, and you could presumably find suitable alternatives at a good, local health-food store. And we do live in a capitalist society and if these are quality products, which I would suspect they are (based on what I read in the book!), then good on them for finding a way to make money. Money just always makes me question someone's true motive, is all.
In any case, these points do not in any way mean that Clean or its products are scam; as I said, you could do this cleanse without the products and I haven't done the cleanse in either variation. I really like the ideals and science behind the cleanse and respect Junger's experience, both personal and professional. I just have a very hard skeptic's helmet that makes me balk at the first mention of profiting from others' health. But the science is sound so I'm trying to mellow out on this here. :)