Why don't you try sucking everything out you can with the electric unit...
Then open the drain plug... I still think the heavy ugly stuff is at the bottom and is better evacuated by the flushing action of the oil...
And then after you have gotten what will come just by opening the drain plug.... try putting a quart of oil into the engine and see what ELSE comes out with that extra flushing action...
Of course you need to change to clean containers for each part of this test..
Yes, that gunk will build no matter what.... because I am describing the gunk which was left with me changing with the plug and hot...
I just think it would HAVE to be MORE with any other method....