Before I tossed it out, I spent some time trying a few rust removal home remedies.
I searched the Internet and found four different methods I wanted to try.
Coke's Verdict: I had always heard that coke could take rust off a nail. This was the perfect chance to play my own version of Mythbusters. I poured some coke into one of the muffin tins then let it sit over night.
Unfortunately (or fortunately if your a Coke drinker) I think this myth is busted. It took a little bit of the rust off but not a whole lot. It might have taken off more rust if I had left it longer, but I really don't want a rusty Coke filled muffin tin in my kitchen.
Hydrogen peroxide mixed with cream of tartar Verdict: I mixed the two together until I had a thick paste. Then using a toothbrush I scrubbed the mixture onto the rust. Bubkiss! All it did was lighten the color of the rust.
Lemon juice mixed with borax Verdict: I mixed the two together until I had a thick paste then I scrubbed the mixture into the rust using a toothbrush. (In case you missed it, that was the exact same method I did with the cream of tartar) It did slightly better then the previous method, but still not much.
Lemon Juice's Verdict: I poured some lemon juice in one of the tins then left it over night. It didnt' get everything, but it made a significant difference.
If all else fails then just do what I did, put your item out of it's misery by tossing it and just go buy a new one.