Not a Grey, but sometimes Salty gets way, way rough with his metal toys ( 2 tubular stainless bells and an all stainless wind chime type toy), both he will attack, similar to how Levi above does it, only he gets almost frenetically fast and involved, squealing in delight. That is NOT the time to see if he wants to be picked up or scratched.
But when he is working on a wood toy, he is more than happy to include me, and he never chews hard on fingers. Salty also likes to play rough away from his toys, with him on his back in my hand and rough housing with the other hand.