When I worked for an auto detailing service, our manager made sure we understood how thorough we needed to be. We didn't just spray a commercial cleaner on the dashboard and wipe it off. We had special auto detailing products and equipment that reached deep into whatever area we were cleaning. We really did use cotton swabs and Q-tips in crevices. I used to take the seats out and steam clean them.
A lot of times customers would want complete auto cleaning and detailing when they were about to put the car up for sale. I can't tell you how much dirt and grime can accumulate in a car over the years, but when we got done, it practically had that new car smell.