ONA PRO Spray – Use it Everywhere! ONA works by actually tackling the odour molecules in the air that cause the smells, then ONA destroys hem to leave no trace that they were ever there! Then use the ONA PRO Spray! It leaves nothing behind to indicate that any odours were present. Nothing! Nada! Zilch! ONA PRO Spray is the best and it is all you will ever need. It is a true odour neutralizer, unlike some store brands that just scent the air.