Ben's pipe reminded me of somthing that I've been thinking about for a while. I love the texture of a well rusticated pipe. But i hate not being able to see the grain. In Ben's pipe you had both, which was really cool. Anyway, i was thinking about trying to bring out the grain in a rusticated pipe.
My thought is to oversaturate the briar with black or brown stain, then buff or sand it back. Once the stain has been taken back to a nice black and white look, rusticate the heck out of it. If the stain went really deep, some of the grain may show though the rustication.
I have found that the best way for grain striations to show through rustication or sandblasting is to use lots of a *light* stain. Some of the best are the Fiebings tan and beige. Lay them on heavy and keep applying until the magic happens.
with limited experience I would say that you'd have an amazingly hard time getting the stain to soak in deep enough to still show on even a shallow rustication like mine. FYI, on mine there was no stain, that's just virgin wood and a coat of shellac.