I was quite impressed while I was going through this thread. When considering carpet cleaning frequency, you should consider how much you are getting traffic. I also have some couple of thoughts on this topic. Although, there are several methods of carpet cleaning like hot water extraction aka steam cleaning, dry cleaning, Dry foam shampoo and Rotary extraction, is a wonderful way to clean soil and dust from carpet. Etc. Instead of using chemicals, detergent or any harmful chemicals, you can use green cleaning products for this work as this products can keep the environment clean. Choosing green cleaning products and materials for this work it is safe for you and your environment.