My way...
what do you guys use to clean ur blocks before assembly?
I use carb cleaner to start with. That gets the worst of the oils off. [Purple Stuff works well, too.]
I then use full strength Mr Clean, engine cleaning brushes, hot water.
Once the washing is done w/ hot water, I immediately spray the entire engine down w/ WD-40. Do this B4 you blow the the water off. If you blow it first, surface rust WILL appear B4 you can get the WD on it.
Once cleaned, WD'd, I go after the cyl walls w/ engine oil and white paper towels. I repeat this until there's no crud showing on the towels.
Once all is clean, I recheck all critical dimensions, and record them on a build sheet, then bag it.
When assembly is about to start, I go over the cyl walls w/ MEK, to remove all the oily residue/dust. I use NO towels on the parts. Air gun ONLY!
Oh ya, I do NO assy work if someone else is there. Bull$hitting cost me a race engine rebuild..Not again!