I use to own and use a hot tank years ago, now I have a shop bake and blast them and then when there done doing all the machine work they put them in their spray washer before bagging and delivering them. The washing does make they make them duller looking than Andys blocks look in his pictures.
I do deburr and do a lot of cleaning before assembling them to make sure all the oil passages and every part of the block is clean enough for brain surgery
AKA aside, you can not keep a engine to clean while assembling them