Since this is sort of a results thread...
I have used SS pins in a rock tumbler I have. A polymer lined hex shaped steel drum. Will clean a nasty looking brown range pick up to look like new. The pins will clean brass that a vibratory tumble will not fully clean. The brass is a burnished appearance and not real shiny. Stored brass even seems to have a certain tarnish look to it. Maybe from simply being bare unprotected brass except for the sealed food boxes I put the brass into after cleaning. I Use Dawn detergent, and Lemi-shine in small amounts in water to cover the pins/brass (small squirt of detergent and couple .45 cases of Lemi-shine). Rinse in really hot water, shake out in a towel and set out to dry or oven dry. Again....the warning on SS pins...sometimes a couple will stick in a primer pocket...very tightly...don't damage a decapping pin or prime into stuck pins. You will need to a 100% inspection in all brass to ensure a pin does not stick to a surface...I have found pins in the rinse even after shaking out in the detergent cleaning cycle. I am sure a pin left in a cartridge could have bad results for a number of reasons. A thought about, cleaning brass....you are making some rather nasty waste. Primer, powder and lead mixed in water or turned to dust. Use gloves, wash hands, keep work areas clean and responsible disposal. At least dump liquid cleaning into a bucket to dry out instead of just dumping into a drain. Take care with chemicals you subject the brass to...some can have detrimental effects on brass causing it to fracture or severely limit reloading life cycles...another research effort...there is a lot of internet talk on the subject.
I have been depriming used brass with a Lee universal de-capper (does all brass sizes, no sizing. just change shell holder to cycle thru brass). Tumble in SS pins to clean off crud and totally clean primer pockets.
Then size brass...have carbide dies for most, but still like to lube some depending on how much force, 300AAC forming, or rifle getting full sized.
Then vibratory polish to remove lube. Lizard litter (crushed walnut from pet store) is much cheaper than gun related media. Couple squirts of Nu Finish car wax in media and run without brass to mix in. Also throw in pieces of used dryer softener sheets (not sure if it really does much but supposed to collect some tarnish...and they do). The brass looks like new at this point.
I like to keep the Nu Finish as light as possible. There is a certain brass to chamber "stick" required to seal the brass when fired. Similar to you want to remove lube from chamber and barrel of a gun before use. Excess burn around the case mouth could indicate a problem and lead to chamber erosion (a warning...do your research).
The brass cycles trough the rest of the reloading process without issue (since a lot of the first steps are done, issues weeded out with easy inspection). The assembled cartridges look factory. The brass waiting for reloading simply has a better appearance and may even resist tarnish better from the Nu Finish coating. Have never had issues with cartridges assembled up to 2 years ago (so can't testify to longer than that length of time). On a side note, the Lee powder dies have a moving part that bells the brass case and is intended to stick to the brass. As the brass is pulled from the die, there is a bit of a thump intended to ensure all powder is charged from the drop and settled in the case...at least that is Lee's reasoning.
In any case, clean brass that is easy to inspect, runs thru the loading process without issue and has a satisfying new look to it. A little extra steps to some reloaders, but I don't like loading dirty primer pockets (although I doubt the residue is of much harm except on critical ammo in which case a pocket cleaning tool may be enough for your concerns).
