With any cleaner, always pretest in an inconspicuous area for colorfastness with a soft, clean, white lint-free cloth. The Michigan State University Extension suggests to get rid of most light dirt, all you need is a slightly damp, soft rag and some mild soap. Gently rub the soap into the leather, and buff it dry with a clean cloth.
A number of deep leather cleaning products are on the market. Some products are a combination of cleaner and conditioner. Biodegradable eco-friendly formulas are also sold. Read the label and product reviews when making your choice. Use water-based products only. Avoid all products containing solvents, silicones or oils, as they may negatively affect the leather's surface. High alkaline cleaning solutions can damage leather finishes as well as the leather itself. Never use harsh chemical cleaning agents, such as furniture polish, ammonia, detergent soaps or dish soaps with grease cutters, as they can break down the leather's protective surface and cause damage. When cleaning finished leather, the main concern is control of both pH and cleaning agent application so the finish is not damaged and natural oils in the leather are not removed.
Dry soil removal should take place prior to the application of leather cleaning agents by vacuuming with the soft, circular drapery attachment to prevent scraping the leather surface. Test the product for colorfastness in an inconspicuous spot. Read product label directions. To clean, apply leather cleaner to a sponge, squeezing to create foam. Apply the foam in light coats to soiled areas in a gentle circular motion instead of rubbing. Wait a few minutes, and blot with a soft, clean white lint-free cloth. Initially, focus on ensuring a uniform application of solution over the entire surface, completing the cleaning process one cushion or section at a time to prevent water spots. Reapply to heavily soiled areas. In some cases leather is extremely dry, and the leather cleaner will dissipate quickly. If this is the case, add 25 percent distilled water to the leather cleaner, which gives the dampening effect you need to release the soil for cleaning. Allow the leather to dry naturally.
At the end of every cleansing, condition the leather. Leather cleaning procedures may remove some natural oils or finishes. Therefore, apply conditioners/moisturizers to maintain the leather's integrity and pliability. In choosing conditioners, stay away from those with oils, waxes and polish. Silicone found in furniture polish damages leather finish. Waxes and oils can leave heavy residues on the surface which will lead to dirt trapping and eventually cause the leather to crack. Following cleaning and conditioning, use a clean, soft towel or similar material to buff the leather to restore some of the shine.