OK, this is off-topic but what the heck - it's interesting (to me, anyway).
I've seen commercial advertisements for the Silver Lightning™ Tarnish Remover Tray
on various television shows, The product demonstration shows a person placing the Silver Lightning plate under water, then placing tarnished silver on the plate -- and like magic, the silver brightens and the tarnish vanishes.
I'm an inquisitive guy, so I assumed this was due to some kind of chemical reaction involving electrolysis, so I searched the web to see what I could find on the subject.
It turns out that silver tarnish is silver sulfide, much of which comes from the trace amounts of sulfur in the air. The Silver Lightning product is apparently nothing more than an aluminum plate, which, when placed in a solution of baking soda and water (about 1 cup per gallon) causes an electrochemical reaction that draws the sulfur away from the silver and to the aluminum.
How Silver Lightning works
This works because aluminum has a greater affinity for sulfur than the silver, and the baking soda solution acts as an electrolyte. Raising the temperature of the water increases the efficiency of the reaction.
The interesting thing is that any aluminum vessel will work - an aluminum pot, or an aluminum foil roasting pan (like the ones some people use for cooking the Thanksgiving turkey) will work fine, and will last forever - and, if you don't have any of those on hand, you can just line a pan with aluminum foil!
Best of all, according to sources I've read, this reaction does not remove any silver from the original object - it's merely a reversal of the chemical process that deposited the tarnish in the first place. So it will not damage your silver objects in any way.
Silver Lighting™ is a trademark of its owner (interestingly, I can't find the registered owner anywhere on the internet...)