Every part of life is exposed to natural toxins in our environment (bacteria, molds, minerals, plant/ animal poisons, smoke, etc). Our bodies have ways to neutralize these toxins so they don't harm our body system. As life has become more civilized, people are living in larger closely located communities, and our processes with farming and industry have changed, we are exposed to more toxins than even before. These toxins can reek havoc on our lifes and health.
The naturopathic paradigm has always viewed toxicity as a major contributor to the cause of disease. Homeopathy is based on the study of toxicology and uses the guiding principle that "like cures like." This involves creating formulas to support health that are prepared with the ingredients that would typically cause symptoms in a healthy person, but having these formulas "potenized" (diluted and shaken up). From the beginning, restoration of health was done by ridding the body of toxins. "Bowel cleansing" was the first known detoxification program. Now, detox programs include many other aspects including liver detox, cellular detox, etc.
Homeopathic cleanse products are designed to support detoxification and overall health. Many people choose to do a cleanse to support their health if they are experiencing feelings of sluggishness or tiredness, or if they are looking to clean out their internal systems. Some people also use cleanses to support a healthy weight.