I've tried "Lexol" (a brand of leather conditioner) that contains Neatsfoot oil, but it only helped until the next time the gloves got wet. From the manufacturer's description at Amazon.com: "You do not have to clean the leather every time you condition, but you must condition every time you clean it."

I shouldn't be so concerned about it, as soon as the gloves get wet they are nice and soft again... until they dry.

tanstaafl.