Carbon fiber rod, nylon and brass brushes, bore guide optional.
I've evolved over the years on rifle cleaning... when I started out, all sorts of fudds said "don't use this, don't use that"... without ever being able to give concrete reasons why or why not.
These days, IMHO a borescope is a must, if you can't see what you're doing, then you're guessing and don't know what you're really doing, so you have no way of knowing if you're actually getting it clean or where the line is between clean enough and doing damage (if/when using more aggressive stuff).
Barrels are made of steel, so if you monitor your work (using a bore scope), there's almost nothing you can screw onto the end of a rod that with fuck up your barrel unless you're actually trying to fuck it up or being a total moron.
I sacrifice a new/fresh brass brush and use abrasives every time I clean now... but since I can check my work periodically and see what I'm doing, my barrels come out better and I can do it without hurting anything. Abrasives (Iosso, JB bore paste, Thorro Clean, etc) are the only things one really needs to be careful with, but as long as you don't overdo it you'll be fine.
For me, along with the bore scope, a chamber rod is a must-have, as it usually takes more work and time to get rid of carbon rings that start to form than it does for the rest of the barrel. A bore guide helps keep muck out of your trigger when you want to go fast and is nice to have, but for me, they're not a must-have.