I don't personally have any experience with any of the "detox" or "cleanse" products out there, but IMHO the best detoxing happens when you feed your body fresh, whole, unprocessed foods like vegetables, fruits, nuts and seeds. They don't have to be raw and you can cook them with all sorts of spices, which are high in antioxidants and potent tonics. You may even consider leaving out meat for a few weeks, and you should feel a significant difference in your energy levels and bowel regularity. After a couple weeks, your body should be flushed of toxins and at least a bit resistant to new damage from pollution and germs.
1) eat real food - more vegetables, moderate meat, moderate fruits, less grains, less sugar, less vegetable oils.
2) exercise - moderate intensity cardio, sprinting, heavy lifting, dedicated stretching and mobility.
3) live - relax, de-stress, meditate.
Disclaimer: I'm not professionally qualified to make any formal recommendations. I've just done my homework and I'm my own guinea pig. All of my data, unless otherwise cited, comes from a sample size of n=1 (me).