Shake the bottle really well, then spray onto a dry wheel in a sweeping motion. Do one, or a maximum of two wheels at a time, making sure to get good coverage. If the product does not get on all the brake dust and grime in the wheel, it cannot clean it off. This is why we like to suggest using a wheel brush. It has a very 'unique' smell that is normal, if you're the rare one who is a bit sensitive to it, we would suggest wearing a mask.
Leave it on the wheel for about a minute.