Need to be careful with the chisling of the carbon crusty oil buildup in the lifter valleys, i have done this to a couple of different cars, and even though you think you get it all out, alot ends up heading down the passages and into the oil pan.
I have cleaned out valetrain areas with cleaners to break up buildup stuff and usually the stuff runs to the oil pan, knowing i need to change the oil anyways, i go through with this. Turns out there is more crud that falls down there than can be seen while cleaning.
One vehicle, my dads, i already knew i was pulling the oil pan because of the way the inside of the motor looked, i KNEW it had a bunch of crap in the pan already, and i'm glad i did, when i did, the oil pick-up tube/screen was caked with stuff, limiting oil pressure throughout the motor.
On the second one, it didn't LOOK that dirty, but after getting everything back together and firing up the motor, it ran fine, sounded fine for a bit, ran it up and down the street a few runs to make sure everything was working good, and then the oil pressure light started flickering, and eventually stayed on constantly.
Pulled it back in the garage, and the top end sounded like a Diesel engine, clattering and whatnot. So i knew right away what was going on, and the next day proceded to remove the oil pan on this Dodge Intrepid (was fun

) and again, sure enough, more crap that i could not see, fell into the oil pan and clogged up the pick-up tube/screen. Cleaned everything in the pan out and reinstalled everything and it sounded like a brand new engine.
Quieter than MY brand new 350 in my Burb,,
So i really don't have a problem or have an issue with removing build-up in an engine with cleaners and whatnot, but i just expect it to be part of the job if i'm going to do that kind of cleaning, to remove the oil pan and do a complete job of it.

Then do a double oil change, cheap oil to flush out any other stuff and new filter, let it run for a day or so, then good oil with a good filter for final run.