General clean and removal or stains/marks
Use a high pressure hose to give a general clean, this should remove any loose surface dirt. If any marks remain you can “spot” clean. Using napisan and water, mix to a thick paste and apply to stain. Agitate on the stained area using a coarse broom. Leave on the surface for a few minutes then rinse with water. Reapply if necessary. Napisan bleaching quality will help remove the stain.
If the area is badly marked, then a weak Hydrochloric Acid Solution can be applied. Dilute 20 parts water to 1 part Hydrochloric Acid. Apply to stained area using a watering can, gently agitate the surface of the paver. Don’t leave on for long, as the surface of the paver may be damaged. Then rinse thoroughly with fresh water.