I actually had a really weird experience with one of those tiny "jug" bottles of Lexol that I have had for I dunno...20, 30 years? When I was trading my old car in 7 or 8 years ago, one of the door panels which must have faced the sun when I parked at work was all dried out (the one on the other side was ok). I mean it was crunchy. I don't think it was real leather on the door panel, but who knows, that was back in the day when cars were cars inside, instead of cheapness.
So I slathered this Lexol on it (which smelled rancid), and left it overnight, thinking it wouldn't do anything. Next day that crunchy "leather" was all soft and pretty much indistinguishable from the other door. However, I don't really like using the stuff because of the "stickiness" mentioned.