Well, O.K., sure you should do the as-needed wipe-down with a damp cloth (and dry) to remove surface dust. Dust left on leather will find its way to creases and act at fine grit to eventually cut open the finish, allow contaminates to work their way into the hide and weaken the leather. Wipe up surface dirt/spills immediately again, with a damp cloth. If you find a darkening of the surface, chances are body oils and sweat are migrating into the hide and WILL destroy the structural integrity of the leather.
There is a huge world of information concerning how to clean leather, BUT, very sketchy information on the actual process. There are multiple methods, steps and considerations when cleaning and nourishing leather. Even if you did have the time, knowledge and the will to clean your leather by yourself, the correct chemistry (and how to use it) is daunting! Two things to consider - body oils and contaminants can go deep into the fiber structure and nourishing the leather after cleaning is VITAL to long-lasting, functional and beautiful leather. Best to leave deep cleaning of your leather to a professional. Why? Give me a call and I'll help you make a educated decision as to how to proceed.