Cool block prep tips

I have been using a propane heater or small torch to drive moisture out of anything I paint or powder. I bet he stole that idea from me.
I like the Mineral Spirits route, though I always though it would leave a film, so I've wiped everything down with Lacquer Thinner afterwards, prior to the torch process (of course making sure it was fully dry first)
I use Mineral Spirits in a jar on a rock tumbler to clean up nuts, bolts & screws. Cleans up grease and rust, fasteners look new. A couple shakedowns in another jar of the thinner to get rid of the sand/glass abrasive.