Sodium sulfite can be oxidized to sodium sulfate thus reducing whatever else it interacts with. I finally ordered some, mostly to use with copper/bronze/brass coins. I searched the above title on Google and turned up with this (about silver coins) and I thought it might be of interest... http://coinconference.com/wp-content/uploads/2016/10/Karda-Lukasz.ppt
That's the way it works. Powerpoint files aren't HTML, and don't display in the browser unless you've set up something on your machine to let that happen. I'd rather have it downloaded than have something try to run it automatically. (Heh. The security configuration on this machine won't let me download it at all, because it's not coming over a secure (https) connection. I got it by manually changing the link to https.)
Hmm... and it looks like copy-paste images are broken in a new and different way today. No more time to spend on it right now, I'll see if I can fix things up later. [Edit: fixed.]
No, sodium thiosulfate does contain sulfur, but it is completely different chemically. Sulfur chemistry names can be pretty confusing. There is a huge variety of different sulfur containing compounds, which have similar but not quite the same names, but they are different.