Only sand a platform when there is an area that can splinter off. If you sand it too much you will expose the staples that hold it together. That can damage your ski or cut your feet. I use a two part teak cleaner called Teak A and Teak B. Amazon's golden teak oil is the best. For best results, clean at the end of the season, let it dry for a month, then apply the teak oil once a month during the off season. Let the last coat dry for a month before putting it in the water. Keep the platform covered when the boat is not in use. One year I found an improvement by accident. I did not have the Amazon's brand readily available, so I bought some Star Brite. I clean my platform at the end of October, and then during the winter months I apply a coat each month. The platform gets a coat of teak oil at the end of November, December, January, February, or March. One year the first two coats I did were Star Brite which is more watery, and then top it off the rest of the time with Amazon's(mdramazon.com). I did not have to clean it again for two seasons.