Wow...that sounds pretty drastic.

Won't a wood shell sound dry anyway, compared to a metal shell (hammered or otherwise)?  I mean, unless we're talking about a really hard, dense tonewood like bloodwood - I can't think of many maple or birch snares that sound brighter than metal shell snares.

If you need to dry up any excess ringing in a wood shell...well, FWIW, to start with, if I were building a drum, I wouldn't use a hard topcoat on the interior surface - just a light tung oil or danish oil to seal up and protect the wood.  Putting a hard, smooth coat of something like polyurethane will diminish the wood's ability to absorb vibrations taking place inside the shell, adding a ringing quality (the sound will keep reflecting around the interior of the drum for that much longer).  If your snare drum has a poly interior coat, I'd sand it off and start with that.

If your drum has solid cast lug casings (versus tube lugs), I'd take the casings off and stuff the interiors with cotton balls.  I've found that on some drums (not all, but some), those little pockets of air can create little "sounding chambers," adding a little bit of ringing and some stray harmonics to a drum's sound.

If more drastic measures are needed, then I might start adding vents - not the big OCDP gaping vents, just standard-sized 3/8" vents, the kind that you can buy grommets for at drum parts stores online.  Just a few of those will dry out the sound of a drum noticeably.  Before you put a drill to your shell, however, I'd suggest taking an old batter head, and punching/drilling a bunch of small holes around the circumference, about an inch in from the flesh hoop - much like some Evans "dry" heads have had done to them.  That will help you get an idea of the effect that shell vents will have on the drum.

Start by drilling one vent, and put the drum back together and live with it.  If you think it needs more venting, then add one more, and live with the drum in that state for a while.  You can always add more vents - you can't really put 'em back in once they've been drilled.

If that doesn't work, or if you don't want to drill the shell, and you want to roughen up the interior surface of the shell, apply a coat of truck bed liner spray.  You can get it at any decent auto supply store.  That rough surface can help dissipate some of the vibrations inside the shell, drying out the sound of the drum.

Or, go with wood counterhoops.  That'll take some of the metallic sound out of the drum.

To be honest, I'd do any or all of the above before I did any major surgery to the interior surface of a shell.  Actually, I wouldn't do it at all - it just sounds really, really harsh to me, the idea of chipping up the interior surface of the shell.  Those are just my sensibilities, however - YMMV.  I just think that there are other, better ways to "dry out" the sound of a wood-shelled snare drum.

If you were thinking about doing that then check out spirit drums because the do something similar. http://www.spiritdrums.com/snare/making.html

That's a good point James.  After checking out the Spirit Drums site and seeing what they're doing, I started rethinking the chisel idea, and, it just so happens that I have a Dremmel.