Yup, a Dremel is the way to go. A few years back Dave(whos work I greatly admire) posted a tutorial on how he did the texture and he used a rotary tool.
I've done a few myself using a ball point tungsten carbide burr then buffing it over to round the jaggedness off.
Thanks, I searched and found his old post. Here it is for all to see, good stuff:
After profiling the bolsters and scales I contour and shape them close to finish up to about 600 grit, remove the bolsters and place them on a secure surface, I have a piece of 3/8 x 1 1/2 x 6 micarta that I put in my bench vise and I use double sided tape to hold the bolster secure.
Before actually texturing the bolster, practice your pattern on a piece of scrap of the SAME material, copper is soft and will machine easier than steel. On this one I did kind of a V shaped layout but get creative and do straight, random, patterns, whatever.
Once you have your pattern draw it on the bolster with a marker, pencil or color the whole bolster with ink and use a scribe. I used a small round burr in a flex shaft dremil with adjustable speed. If you want highs and lows just apply more downward pressure in some areas, be careful towards the edges as the burr wants to roam so hang on tight, use short strokes with the burr then overlap and blend as you work your way down the bolster
Once you finish texturing with the burr take a small dremil wire wheel I use brass wire on this one and wire wheel the entire textured area. I then reattach the bolster to the frame with scales and I sand with the same 600 grit to blend the bolster / scale joint and you can apply more sanding pressure to the texturing to flatten the highs some, depends on the look you're trying to achieve.
Take the bolster back off and put it back on you're steady rest, now you can apply different patina's, on this one I used a browning patina over the whole area. Once you achieve the color you want stop and rinse it off with hot water and LIGHTLY 4 / O steel wool the texture. Dry it off and I did an oil rub on this one to give it a more soft burnished look. I used gun oil and a stiff backed very fine sanding cloth and rub it until you are happy with the results. I finished with a couple of coats of ren wax.
That's it, hope it helps and have fun trying different methods, Dave