OILS extracted from lemons and oranges are good at cutting through grease - something demonstrated in Indian restaurants where lemon-impregnated hot towels are handed out at the end of the meal. Pronatur Products has been applying the same principle to cleaning land contaminated with hydrocarbon wastes. At the Tyseley rail depot in Birmingham, land contaminated with waste oil was sprayed with a solvent extracted from the skins of oranges; this treatment was followed by a second spraying - this time with a cocktail of microbes. Using microbes to clean such land is not new, but can often take years unless the oil is first broken up using powerful detergents or solvents. Orange oil extract speeds up the process without using damaging solvents or contaminating water courses.