Do a search for CLEMCO.
They manufacture abrasive blasting equipment.
Plastic beads or glass beads work well on many parts. Many other blast
medias are also available.
There is a material which is a coarse form of baking power. Works well
and does little base metal removal but removes coatings and light
surface rust.
DO NOT USE SAND!!!!! Many dangers and problems with sand. It is
outlawed in many countries but still widely used by many in the US.
Black Beauty is an angular abrasive which will leave your surface too
rough.