Sandblasting the yoyo will not give it a raw look but rather an almost bead blasted look which will help for grinds. If you wish for a raw look, I would sand the yoyo. Also, if you do plan on sand blasting the yoyo, I would recommend you do not sand blast the inner wall of the yoyo as it may fray the string very quickly.
If you want to sand-blast the whole thing to make it amazing for grinds, just take a worn strip of leather and rub it around the bearing seat and recess. This will soften the surface.
do what jm said but if you want a raw look you can ether sand with a 220 grid water sand paper or use grease lightning although i never tried it i was told it works on other like rc cars and paint ball guns but i dont know. Playing with chemicals is never a good idea
Do not sandblast your yoyo. It is too abrasive and it will ruin your yoyo. You either need glass beads mixed with pecan shells or just beads. Sodablasting will not remove anything. It will give it the most amazing finish though.