In my hands, at least, I have had no issue with using Lexol conditioner on whiskey, natural, or ravello shell. If darkening is the concern, I find that it recedes to the original color within a day. Of course YMMV
If we're thinking of the same source, Nick didn't actually recommend VSC for conditioning. He just said, "oh that's what we use here before we send it out". It wasn't quite part of a recommended long term care regimen for shell.
[[SPOILER]] In my experience with dry C&J shell like that, the only thing that works is Lexol conditioner. It works where Saphir Cordovan Cream, Saphir Reno, and VSC have all failed - none of which actually conditions well, in my hands.