Lexol. It has been used by horseman on saddles for decades and is the best cleaner/conditioner on the market. My '98 explorer was sold (snif, snif..) and the seats looked new after 7 years and 130k miles in So Cal weather, all I did was Lexol the seats every 4 months. Dirt wears leather down really quickly. You can get it everywhere, it comes in a small brown jug.