Stovax Slate Dressing Slate Oil Polish 500ml Cleans & Polishes Any Slate Surface. Stovax Slate Dressing Oil seals and protects tired looking slate, enhancing its natural beauty. It may slightly deepen the natural colour. The dressing repels dirt and water whilst allowing slate to breathe. Directions for Use: Shake bottle well before use. Cover and protect all fabrics, carpets etc. Ensure surface is clean, dust and grease free. Using a soft lint free cloth, apply slate oil evenly and sparingly. Allow 2 hours to touch dry.