Clay bars take out all the contaminants that have embedded themselves in the paint. They do not remove scratches, swirls or anything else. They are very simple to use. First wash the vehicle very good. Then get a clay bar and some quick mist detailer, mist a small section and then rub the clay bar over it, do not let the area dry, and then wipe clean with a clean towel. Fold the clay bar frequently. If you drop the clay bar on the ground throw it away or it may pick up something that scratches the paint when you use it. Afrewards you will want to wax the vehicle. Completely do a small secton first and then compare it to the adjoining area...makes a pretty good difference. i have my vehicles clayed once a year along with polishing and then waxed every 4 months.