Do "cleanse" diets detoxify your body and/or help with weight loss?

Also known as the "Lemonade Diet," the "Maple Syrup Diet," and the "Master Cleanse," this diet entails several days or more (up to 10 days!) of consuming nothing but a lemon juice, maple syrup, cayenne pepper concoction.  On an episode of The Office, a company-wide weight loss competition spurs Kelly to consume only this drink for several days. Eventually, sweaty and lethargic, she collapses in her cube, and her panicked co-workers don't know what to do!  The idea behind this diet is to "cleanse" your body of toxins and "rest" your digestive system.  It is also supposed to jump start weight loss.  This diet is extremely low in calories, and devoid of protein, fat, complex carbs, and nearly all the essential vitamins and minerals.  If you stick with it for several days, you will undoubtedly lose weight from the extreme calorie deprivation.  However, your body will also go into starvation mode, your metabolism will slow down to preserve your body's energy stores, and the moment you go back to eating solid food you will gain weight due to your slowed metabolism.  There are no special magic nutrients in these ingredients - lemon juice has vitamin C and cayenne pepper has capsaicin, but neither of these will especially detoxify your body or "rest" your digestive system.  Your body is really good at cleansing itself: your liver, kidneys, and spleen are all full-time body cleansers, and they don't need you interfering with their normal function.  Saying your digestive system needs a rest is like saying your "heart needs a rest" and should stop beating for a while (and you die).  You need protein, carbs, fat, and vitamins everyday - and this cleanse diet will just screw up your metabolism and deprive your body of essential nutrients.  If you want to feel healthier and naturally cleanse your body, cut out all junk food from your diet (fast food, pop, candy, Little Debbie snacks, chips, anything processed), eat more fruits, vegetables, and fiber, and drink some extra water and maybe some nice green tea.  The cleanse diet is touted on lots of websites and blogs as a great thing to do - but this is all quack science and they just prey on people's desperation to be healthy and lose weight.  Don't believe the hype - this is all bogus and a bunch of crap.  The Science Lady cannot make this point enough - the cleanse diet is dangerous, bad for you, doesn't cleanse anything, and only makes losing weight harder in the long run!