I wish I could show you the loveliness that was my platter before my laziness of not washing it by hand occurred, but, alas, I don't have one.
But, here it is after the dreaded wash. I wiped it down as best I could so that the black wouldn't smear on my hands anymore, so it's not quite as dark as it had been before that.
The first thing I tried was putting foil in my sink and laying baking soda down and then filling the sink with hot water.
Anyway, next I tried toothpaste, again to no avail. The difference was so very small that it wasn't even worth taking a picture of.
Consensus: If you are in need of a good tarnish remover and can find some Tarn-X, get it. That stuff works wonderfully; stinks horribly; but it works. My mom has used it for years. If you can't find that, this is an ok alternative...though, it certainly didn't give me back my beautiful platter like I would've liked. My next step is to try out Tarn-X again. Oh how I hope that will work!