I have several silver cake plateaus and they are starting to discolor. What do you use to get them back to their original luster?
I use toothpaste to clean the tarnish off my silver jewelry. Just rub it on and work it into a foam with some water. The silver comes out shining like new!
I imagine the same would work for silver plateaus, but I haven't actually tried anything beyond jewelry. There are also specific cleaning products you can get for silver, but I find toothpaste to be just as effective (and likely cheaper).
Try lemon juice. Once when I was moving and couldn't find the silver cleaner, my friend started cleaning mine with lemon juice and they came out beautiful. And of course it is enviromentally safe, lol