I just used Obenhaufs LP on my Iron Rangers from christmas. I've been wearing them every day since then and they were thirsty. It darkened them a LOT but i can see as it works in and lightens up in the less worked areas its going to patina nicely in another month or so. I clean them with water when needed but this is the first oil treatment. I will likely not do it again till the 1 year mark. every 6 months maybe?