There's no point in thinking that detox will completely rid your body of the amount of pollutants and pesticides it encounters. 2 days of eating vegetable stock isn't going to turn you into a new person.
The best way of preventing the build-up of waste in the body is to reduce your exposure to toxins by not smoking, limiting your intake of coffee and alcohol, eating unprocessed food (preferably organic). A detox plan is a really good way of starting you off on the path to a healthier diet and lifestyle, so by all means use it to kick-start a 'new you.'
Medical practitioners all agree that starvation detox diets are not good. Not only do they weaken your body by depriving it of the nutrients it needs to function properly: it actually produces the opposite effect to the one you want because it aids the production of toxins!