I don't know whether Karsch used this effect or not, but a green filter makes reddish skin more porcelain-like. I think Maplethorpe used it for many portraits.
Sorry to see you unregistered; that isnīt how you change the world for the better!
Anyway, silver-looking prints are also given that look if you use old developer. In the days of wetness I used D163 for as long as I could find it, but Kodak had set the self-destruct mechanism into motion even way back then, and I was forced into using other brands whose names have long escaped me (Iīm thinking of the very early 80s here). This was not a precise science, but it did have its benefits, even if by virtue of serendipity alone!
So, if you have the storage space and are also willing to work with the revealing properties of glossy paper well glazed, try keeping a bottle or two of used developer. Not when itīs already brown, of course, but whilst it is still pee-coloured. Fresh pee.
Much of the work I did was studio stuff with umbrellas (white) and yes, they do give a soft light, but even that varies with distance, of course. The trouble with much studio-based work is that it is often used for speed, something which leads to standardised lighting setups, which can become boring (to the photographer) even if delightful from the clientīs point of view.
Perhaps a large problem is present today (in copying īlookī) by virtue of the fact that itīs often done via different print routes: digital does not look like photographic (wet) when held in the hand - reproduction is something else and not everyone can tell with certainty whether a print in a magazine or book comes there via desktop or darkroom. I assume that the silvery look concerning the original post is with prints, not reproductions via the press...
As for Maplethorpe - the least (in my humble opinion!) said the better.
Ciao - Rob C