Shiny brass -- it may not shoot more accurately, but it does make you feel better about your hand-loaded ammo. While it's not necessary to get brass bright and shiny after every firing, it is a good idea to clean powder residue, grime, and grit off your brass before you run cases into sizing dies. There are many ways to clean cartridge cases.
Frankford Arsenal Ultrasonic Brass Cleaning Solution
Creedmoor Sports Brass Care Cleaning Solution, Creedmoor Sports
Buy Rotary Case Cleaner and More
How to Sonically Clean Brass Shell Casings - iUltrasonic
Daily Bulletin
UltraSonic Case Cleaning
Cleaning Solution for Tumblers and Ultrasonic Machines
Brass Cleaning Options — Tumbling, Ultrasonic, Chemical & More
Ultrasonic Instrument Cleaning Process
Turbo Sonic Cleaning Solutions
April « 2019 « Daily Bulletin
Test: Case polishing and cleaning methods with the Hornady M-1 and
Buy Rotary Case Cleaner and More
Play With Your Food: Clean Brass With Rice :: Primal Rights, Inc