Some will say no, other (like myself) will say yes. Boils down to this for me....clean brass equals:
1. Better for your dies (especially carbide)
2. If your brass is "picked up brass" ie...at the range after others leave it, it will possibly be more dirty(dirt, sand, and the like). who wants to hand rub this off?
3. Going for a "tuned" re-load for gun? MUST be clean.
4. It just looks better
Clean all the way for me, you can get a good tumbler for around 50 to 60 bucks and media can be cheap, there are tons of post about this. Its worth the time and effort.