To each his own, I'm just stating physical facts about what the different methods will do. Sanding tears up the surface, acetone does not. If you mess up with acetone, you do have a fair chance to re-dye and fix the mistake- something you can't do when you've actually destroyed the pores of the leather beyond a certain point. (And you can apply a little bit of acetone to a cotton swab to try. The acetone will do exactly what you are describing, without damaging the surface irreparably.
I've done a fair bit of experimenting with this, even taking apart a long leather coat once, taking out essentially all the dye from it. I also have a pair of dress shoes that I wear with suits- originally the toe was in a metallic color I didn't like, so I took it off with acetone, then applied black dye and polish.
Also note I didn't suggest scrubbing with a steel brush, just scuffing... and then sparingly. Huge difference.
The main thing that's hard to do once you've used acetone is to get back a high gloss... i.e. something close to patent leather. (It's probably possible with enough buffing, I just haven't done it.)
If the sanding method works for you, then great... go to town!