Scotch Brite is really the only thing that I use to dull a ball up by hand.  Completely safe to do it by hand, but some people prefer to use a little water to keep the dust down.

I do have some Ebonite Powerhouse Matte Finish, but the results by hand are less than to be desired.
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"A word to the wise ain't necessary -- it's the stupid ones that need the advice."  Bill Cosby