Well, it's impossible.
If you've spent any time at all around the natural/green cleaning world specifically, you'll hear all about how bad it is to clean our homes with chemicals. You'll also find plenty of people willing to explain how to keep your home clean in a "safe, chemical-free" way. Unfortunately, it's all a bunch of pseudoscience and ignorance.
I'm not opposed to using less risky things rather than Comet or 409; I use baking soda and vinegar all around my house to clean all kinds of things. Aside from blue Dawn soap or water, baking soda and white vinegar are what I use the most, because they're really effective.
Well, baking soda is a chemical (NaHCO3). Vinegar is also a chemical (CH3COOH.) Water, "the universal solvent" is also a chemical (H2O). In fact, everything around you, everything on Earth, everything you eat, even you are made of chemicals!
Don't believe me? Consult any basic chemistry text book. Or even Bill Nye the Science Guy. He did an excellent episode for children about Chemicals is which he emphatically declared that everything is made of chemicals.
So, if children can be taught and understand this, then why do adults who choose to promote "natural/green" cleaning insist on declaring that you, too, can achieve a "Chemical-Free Home?"
(Side note: I mostly don't blame the individual essential oil consultants, like the one pictured above. That person is simply sharing the company line, repeating the things the larger company promotes and has deceived it's sales force into believing.)
"Well," they might say, "it's just an easy, short-hand way to express what I mean. You know what I mean!" Nope, I don't know what you mean because with your oversimplification you are manipulating a basic scientific concept, encouraging ignorance, and preying on the fears of naive people. Plus, you're just making yourself look uneducated. I would think that if I believed in a cause, I would not want to unwittingly say something that undermined said cause.
"Ok then, we can just say 'man-made chemical' free." This doesn't work either. Neither does an argument against "toxic chemicals" or "poison." This article explains it so succinctly: "A common misconception is that all man-made chemicals are harmful and all natural chemicals are good for us. However, many natural chemicals are just as harmful to human health, if not more so, than man-made chemicals." Also, "Everything is poison. There is poison in everything. Only the dose makes a thing not a poison." Another good article can be found here.