I have a frog that has some very bright and shiny rivets on it that I'd like to antique. I tried some mustard and some vinegar and there's no noticeable difference, so I'm guessing that they're stainless steel? Does anyone know how to go about staining stainless steel?

Give it a fabulously vigorous scrubbing with an honest to the Gods Brillo pad. It'll do a nice job of staining your stainless. And throw in some 1500 wet-dry paper for good measure. If you doubt, call your mom. She'll say "NEVER scrub stainless with steel wool!!!" And then you'll know you're on the right track.

try the old fashioned way - fire via a propane/butane torch or hot coals. i have found pulling the steel out with tongs while still hot and rubbing down with mineral oil helps to "set" the coloration a bit. if you don't like how it turns out - scrub down with scotchbrite pad and try try again