They should practice an average of half an hour a day. No previous experience or special clothing is necessary and you can practice Qigong anyplace. Qigong quiets the mind by allowing you to let go of your thoughts. When you're not looking into the future or the past, then that energy can go into your healing. You're taking that energy and working it with the body, balancing the organs.
Movements stimulate the meridians.
For instance, you have a movement for the spleen where you're stretching the meridian and stimulating it, and at the same time your making a sound that helps detoxify that specific organ. Some people come in to Qigong wanting to learn the most exotic movements and ask what master I studied with. But Qigong is about practice. The more you practice the more you get in touch with your own body, the more meditative you become, the more you start feeling things in your own body. The six healing sounds at first seem little more than sounds, but the more you do them the more they begin to trace back to a memories stored in your body.