I've used SS in lab processes, photography and all manner of other applications - cooking, gardening, woodwork.. never had ANY of it rust and I've thrown every sort of godawful chemical combination at it, left it wet, scoured it, boiled petrochemicals, shocked it with ridiculous pH changes, heated it to red heat, poured liquid nitrogen on it (I make the BEST dry martini on the planet, no contest) and I've never had any trouble with any of it apart from on motorcycle header pipes where they (as expected, really) went all rainbowy on me and where the missus burned rice to a cinder in my favourite saucepan, leaving a permanent slightly-darker area which I don't think is a stain but the result of her screwing the temper on the metal. THAT is serious abuse. The pan, however, has never rusted or exhibited any signs of hardship apart from the slight colour change/

For "clinical" and laboratory applications I've avoided wire wool and used bronze or pumice for scouring if necessary but apart from that I've never really done anything too special with any of it apart from repassivating when I've had to, say, scrape epoxy off it or fix some really dumbfork excursion into my stupid zone.

SO - I'm seriously wondering wtf is going on here. The dissimilar metals, crap ss specification or unbelievable level of user abuse are certainly suspects, but frankly I'm amazed. There again I've probably never soaked anything in vinegary salt - it wouldn't have occurred to me, just s filling a frying pan with flambéed weasel manure would never have occurred to me. Now it has, and I'm curious. Dammit.