Depending on degree of cleaning needed, power wash or hose loose dirt off of the trim board. If using a power washer, be sure to test the pressure setting and nozzle first to ensure that the surface of the trim will not be damaged. Other cleaning methods include using a soft cloth and a mixture of mild detergent. Some people have found the Mr. Clean Magic Eraser to work on pencil or other black marks. Other methods include mild household spray cleaner like Simple Green or Krud Kutter Cleaner/Degreaser, Oxiclean, or denatured alcohol. When using cleaners other than a mixture of mild detergent and water, it is best to test on a small area or a scrap piece of BOTO Trim, to make sure it does not harm the surface or damage the product’s appearance. Always read the cleaning product manufacturer,s specific information before using any product on your BOTO Trim and follow their instructions. WARNING: Keep children and pets away from cleaning product and the Trim until completely dry. IMPORTANT: Do not use solvent based cleaners as they can harm the finish of BOTO Trim. Consult with your paint manufacturer for instructions on cleaning BOTO Trim that has already been painted.