Best way to clean an engine block?

I am in the process of working on a Gen III hemi short block. As I was investigating things I am finding a lot of trash in the block and oil galleys ( I did not build the short block). I understand the short block needs to come 100% apart. After I do that, what method would you guys use to clean it? Thank you all for your advice. I will try to add some pics of what I am discovering. It looks like a mix of sand and assembly lube. Turned the cam over by hand about 3 revolutions and you can see what happened to the bearing. Did that before I saw any trash. The bearing looks worse than in the pictures and I can catch my fingernail on the grooves.

I would remove the cam bearings and have the block derusted, hot tanked in a caustic solution

Yeah I am not too thrilled with the rust either. I am trying to learn here- if the block was hot tanked and de rusted, will that require the bores to be honed? Already have pistons and rings and don't want to change them. The bores look perfect and the rust is limited to the un machined portions of the block.

Years ago a friend and I went in together on a hot tank we bought from a local tool dealer or maybe a parts store, bottom line it ran on 220 V and the caustic soda would wear out with use and it had a derusting chemical in it that may not be available now with the new environmental laws
It worked great
I don't think it would eat cast iron though

I just use a can of gunk, engine brush kit and hit block with pressure washer. Evaporust will remove all rust. 2cts.

I agree, I have a home built hot tank, and I wouldn't put that in there. Not worth it. On the bores the caustic soda won't eat them but it is so good at breaking down any oil that by the time you begin to remove it from the soda and rinse it down the bore get a little flash rust. Which might be ok but you will be scotch briteing it out for sure.

Thats all I do.. start out at the 25 cent car wash then head back home.. I have had a shop clean them
a few times but usually do them myself unless they are really bad

If it the weather is warm out I do the same with my pressure washer. Pipe cleaners, oven cleaner, and gun bore brushes help. Derust with home made electrolysis tub instead of evaporust. Just make sure every galley plug is pulled.