Very nice drawing, Michael. I enjoy it when the pros post work in various mediums.... as I'm sure the clients appreciate the different price points in this art of portraiture.
I think the reason everyone keeps getting back to sauce is that it seems to be what charcoal aspires to be, at least in terms of rich, dense darks, and in variety of application. In other words, it's so versatile and painterly: you can apply it dry with a ponce pad, or work wet with bristle brushes, or lift off with an ink eraser, or even use the sticks like pastels.
On another forum, another artist pointed out that various mediums can be utilized in a sauce-like manner. For example, Scott Burdick grinds conte crayon, sometimes charcoal, and sometimes perhaps other mediums, I don't recall, and the powdered form gives him a very "sauce-like" variety of application.
Here's a link for anyone interested in his "sauce-like" application.
Here's another, where it looks like conte was ground up and applied in various ways.