Cylinder head cleanup, cosmetic

What processes are engine shop’s using to clean blocks now? With all the aluminum blocks and heads these days they got to have something safe. I need to get a 340 block cleaned and sonic checked so I might ask if it isn’t done by then.

I will stop at the hw store tomorrow and see what kind of non-aircraft aircraft stripper they have. Got some ZipStrip in the cubbies but seems to be oriented at wood. Contains Methol chloride, methanol,and mineral spirits.