How do you clean pewter?

Had already tried a couple of commercial products - Brasso, Bartenders Friend, others. Then the internet thing said that white flour plus white vinegar was JUST THE THING. Have bought flour about once in my life before, but did it straightaway!1 Already had the vinegar. So what hoppen?!1 Supposed to make it into a paste, let dry. Did this, and some of the really black maybe cleared up a bit, but in the end no shininess or brightness.

Maybe this thing is not pewter? Doesn't matter that there are beaucoup nooks, crannies, or otherwise orifices (not really orifices, just being non-cute), since the flat surfaces don't shine now.