I’m coming late to this, but want to comment that there aren’t that
many absolutes. I have seen posts saying not to store snippets as
they will oxidize - I store mine all the time with no trouble. I use
a glass jar that formerly held pimientos, very well cleaned. One for
each sort of solder snippet. They can sit for months with no problem.
I suspect much is in HOW you store or use something.
I use steel wool to clean silver before soldering sometimes, and
have never had a reaction. That said, I don’t leave bits of steel
wool on it!
Your mileage may vary.
Three Cats and a Dog Design Studio