I've done the old common chrome pedals with great success. If the bearings have grease on them, the Oxalic Acid doesn't penetrate to the metal. Same with other parts - chains and such. I've saved a bunch of chains, but they have to be dry and rusty, free from grease and dirt.

Soaking a whole frame would be a grand experiment, but I'd try it on one I didn't care about first just to be sure. Something like a $5 Magna. A chrome wheel bath is definitely a time-saver - learned that from a fellow BF member. Just mix your solution in a wall paper wetting tray, and rotate the rim every so often. Sure beats scrubbing and polishing.