Interesting explaination and I too am interested in this subject because my wife is often shocked getting out of my cars, NOT just one car either btw. She's complained about this with (I think) every car I've owned yet I don't get shocked ever. Doesn't matter what tires I'm running either BUT yes, it's worse in winter when dry.
The tire idea is interesting BUT when seeking new tires, one usually has various reasons for selecting a tire (performance, handling, wear) and in all my years, I've never once seen where any tire manufacturer mentions percentage of "carbon black" or a tires ability to ground vs another.

I might try a grounding strap just to see if she complains less. Those shouldn't wear too fast really in that when the car is moving, they shouldn't be dragging on the ground, the moving air should keep them floating.