best rags for assembly

I still haven't found the "perfect" rags/wipes for engine stuff although my top choice is probably washed or at least rinsed 100% cotton t-shirt material, less than 100% (old sheets, etc) I use for soaking up spills on the floor since it's much slower-absorbing. Pretty much all paper-based wipes leave lint behind if you look closely enough especially if it gets caught on a sharp edge like the cooling jacket holes on the deck of a block or any rough cast surface. There are special laboratory-grade paper-based wipes commonly found in chemistry labs that are called Kimwipes which I used in grad school for cleaning sensitive electronics and gas plumbing parts, they are pretty thin and have a weird feel to them but damn they work as advertised, ZERO lint! I might give them a try when I start putting together my 440.

Kimwipes® Delicate Task Wipers

Also I agree the only sure-fire way to clean parts and leave behind absolutely no particles or debris is a strong spray with solvent like brake cleaner and then compressed air with no direct physical touching at all. I figured that out when rebuilding the valve body in my 904, literally anything I touched the separator plate with aside from my bare clean skin left behind small particles which could get stuck inside the tiny passages or prevent the parts from seating together properly. And even clean hands can still leave behind residue which corrodes metals.