I've never felt my Frankford Arsenal tumbler get so much as warm from running it overnight. It's a valid concern, but a minor one IMO. I like bright shiny brass being in the PNW. Any finger oils or darn near anything on the brass makes it quickly discolor and begin tarnishing. If I lived in a dryer locale, I probably wouldn't bother. It's partially a pride in my product too. Think about it, would you buy new ammo if it wasn't bright and shiny....not me.
+1 on dryer sheets, it makes the dusty grime issue a thing of the past and has more than doubled the life of my walnut media. Actually, probably more than doubled it. It really grabs the crud well.
As for that stuff with the red rouge on it, it works well also, particularly on stubbornly stained brass. Lyman Turbo Polish is the product. But you have to either clean them again in walnut media or live with that red rouge on your brass.
Nu Finish works really well and is economical when compared to Flitz and other reloading specific tumbler additives. But the manufacturer knows their customer base and what they can charge, so they do. I have had great luck with Flitz polish also, but the price is disturbing when you compare it to an equal amount of Nu Finish. Something like 3 or 4 times the price.
Another example, you can buy a few pounds of walnut media at your local outfitter and you'll pay premium prices for it. If you goto a pet store for Lizard Litter, (also crushed walnut media) you'll get something like 15 lbs for less than half the price of that couple pounds at your outfitter. Proper marketing can make most people buy anything if they can create a perceived need for it. Don't think so, just check out any teenagers wishlist and you'll quickly draw the proper conlcusions. (a LOT of adults too, think Hummer)