Getting parts cleaned, What do I ask for? Options

[mikesmith]

This was prompted by a door latch mechanism covered in decades of gunk, but the question's more general; since my cleaning resources basically stop at a can of brake cleaner and a plastic basin, if I want to get something cleaned properly, where do I go?

There's a machine shop down the hill that probably has the sort of equipment that could get stuff clean, but what do I ask them for, and are they likely to be interested in one little grease-packed doodad?