Brake dust is the most stubborn contamination on your wheels. Those iron particles eat into the lacquer or bare metal if you leave them too long. A good wheel cleaner dissolves them chemically without hard scrubbing, but the difference between pH-neutral and acidic determines what is safe to use.

On coated, polished or anodised wheels you always want a pH-neutral cleaner. For stubborn brake dust on untreated alloy you can step up to an acidic cleaner or iron remover. Always read the product description so you know exactly what you are working with.