Timberkast panels can be sprayed clean with a garden hose. For tougher spots, use a mild soap, mixed with water, and rinse.
If you want to spruce up the doors after a few years, you can use a clear matte, urethane coating from your paint or home improvement store. One product, Minwax Helmsman® Spar Urethane, is a specially formulated protective clear finish available at most hardware stores. Periodically applying the urethane clear coating to your panels will help protect them and also maintain their factory original look.
Deep gouges or scrapes can be addressed by using wood filler and a color matched exterior latex or acrylic glaze. If you have more extensive damage, please contact your Timberkast representative for advice and assistance.