The answer to 'natural upholstery cleaner' is to use a homemade solution of mild dish soap, white vinegar, and water. Mix 1 tablespoon of dish soap, 1 tablespoon of white vinegar, and 2 cups of warm water in a spray bottle. Lightly mist the upholstery, let it sit for a few minutes, then blot with a clean, damp cloth. This natural cleaner is gentle on fabrics and won't leave behind harsh chemicals.
For heavily soiled or delicate upholstery, it's best to call in a professional cleaning service. They have the right equipment and expertise to deep clean your furniture without causing damage.