I jet wash mine to remove the oils, etc after maching, I then put it on a cart and power wash it with hot soapy water, I brush out all oil passages and then final rinse it. I might add that I always final wash AFTER I have put the cam bearings in to wash out any material that might have skinned off after installing them. I flood all of the oil passages thoroughly with clean water. I blow it dry and then hand clean the cylinder bores with lint free cloth, then yes, clean toilet paper. I keep wiping the bores down with light oil until the toilet paper is perfectly clean with no residue on it, then I know the bores are clean and oiled.
I always get soggy when I final wash a block, but I have as yet found a way to keep from it.
I don't like to re-hot tank blocks in dirty hot tanks. I've always felt that there is too much of a chance of actually putting debris back in somewhere as opposed to removing it.
For DIY guys, the car wash and the pickup bed is a pretty good final wash, although you might get accused of being a red neck, but who cares, all that matters is a clean engine.