...don't stipple your Glocks. It will kill the resale value as a lot of us would never invest in a cut or modified framed gun.
Much better to sell your older gen Glocks and buy a gen5, with the newer more aggressive grip nubs.
I'll shut up now. Carry on...
If I were to stipple I'd use my laser engraver....I agree. For future readers, if you don't like the finger grooves, get a Gen 5. If you don't like the texture, Talon makes precut grip tape in three textures that look great, aren't going to come off by themselves and can be removed cleanly with a blow dryer.
Any time I see a stippled gun up for sale, it gets an immediate pass.
With that said, if I 'was' going to remove the finger grooves, I would use a 1" drum sander in a dremel or more likely, a larger, drum sander in a drill press and appropriate files. Sandpaper wrapped around various shaped objects would also be useful.