I, too, have Magnalite that I've had since the mid 60's. I cook everything in it. A little Bon Ami will help remove any stains but, frankly, I've never had anything (even tomato) stain this cookware. But I do wonder if the acidic tomato contributes towards the pitting in the interior of my Magnalite, something I have noticed in the last few years. Unfortunately, I've not only noticed that my Magnalite has pitted (interior) but it has also darkened (both surfaces)--probably, through misuse per cleaning. These things may just be a sign of old age (and I have plenty of that, too
I have a question, though, of those who have had Magnalite cookware for several years. Is there any way to brighten it up? I foolishly put mine into the dishwasher--in my ignorant youth
--and it has turned quite dark. Scouring powder (although I won't use Comet or any harsh ones like that) does not brighten it up. Most of the good metal cleaners, like Brasso, are so caustic that I will not use them on cookware or anything that comes in contact with food. I would love to get my beloved Magnalite roasterette (yep, that's the name on the bottom) all brightened up.