Microfiber cloth ( no lint this way) hot water VERY mild soap solution. After soaking cloth for a few moments ring as much water out of cloth by twisting tightly. Use a steady back and forth motion on a well vacuumed seat. Making certain not to press very hard which will only extend the drying duration. If you can find it use Meguiars Mirror Glaze Professional interior shampoo/car wash # 62. Just a very tiny drop in a few gallons of water.