I myself have never done one but I looked it up and basically in a nutshell, it is a do-it-yourself detox/cleansing program, for three weeks you'll eat no dairy foods, no meat or animal foods, no white flour, no sugar, no soy, and no salt. You start with vegetables (and fruit) only, they can be cooked, then you move to raw veggies and fruit, then onto juices only. It is essentially a type of fast and when you are done, you have to slowy start eating again in reverse of how you started, however you should not return to eating unhealthy and processed foods (much) when you are done.
JoyceP