You can feel these as you run the cloth across your hand. It will catch in the ridges of your skin. Cloths can actually eliminate the need for chemicals to clean. They do a fine job cleaning windows and mirrors with just a spray of water, though they won't take off hard water deposits or scale. They also clean grease film from the stove with just a water spray.
Heavy crud needs more.
I find I tend to use them with a water spray first, then go to chemicals if there is still stuff left on whatever I am cleaning. Great for picking up spills, too, as they absorb a lot of liquid quickly. The little places on the cloth will fill up with fabric lint over time. Package instructions advise hand washing instead. The contract would need to specify lighting of a certain standard, etc., etc.