How to flush out a new build

Thats the first thing i do when i get a block back from the machinest is run engine cleaning brushes thru it and flush it out. Even if the machine shop says they cleaned it, you are the last line of defense before it goes together.
Maistrelli why do you disagree with that statement? I subscribe to the thought process that YOU as the end assembler of it are the LAST line of defense ! I work in the aviation industry. I take NOTHING for granted when putting something together. Oh it's the other guys job to do this or that doesnt cut it in aviation mtx. That's real expensive stuff that can kill people if it fails. If your building something like a car engine that's high dollar money for you, which by the way is still a drop in the bucket compared to aircraft parts, then you should be taking the same care to make sure its antiseptically clean before reassembly.