As long as you realize an oil stain does not affect performance and is strictly a cosmetic issue, feel free to use the following...

Here is a link that might be useful: Carbon-Off

Joe,

Have you tried this cleaner on old cast iron with the intention of cleaning to bear metal? I am not familiar with this product.

Dan

Thanks, and that is okay on the anodized aluminum?

Why do you care about a grease stain on a pot you will be cooking in....which is bound to get more grease stains? it still cooks every bit as well....and if the grease stains bother you...buy stainless or enameled cast iron.
Suppose you put the carbon remover on the pot and it takes off some of the anodized coating? Will that make you happier?
Wash the pan so it's claen and ignore any grease marks.
Linda C

Dan: I haven't used Carbon-Off on cast iron, mainly because my CI cookware is in tip-top shape! I have used it on some plain aluminum, and some Weber grill parts, and have no complaints. I found the initial recommendation for Carbon-Off over at eGullet.

SoCalGal: You'll note that the website says DO NOT use on Calphalon Non-Stick cookware. Again, if you feel the need to remove the stain, try a test patch on the bottom of the pot before proceeding.

That carbon Off looks interesting! I also like my pots and pans to look nice besides cooking well so I know how you feel!
Joann

Hi, I posted on the KT about cleaning aluminum and here is what I learned and it worked.

Make a paste with cream of tartar and lemon juice, rub it onto the area to be cleaned (I did an entire pan) let it set and dry about an hour or so. Scrub if off! My pan looks like new

cheryl ok's method works well for some stains. On my anodized pots and pans the stain is sometimes a coating of hardened oil. I've found you can get it off by carefully using a single edge razor blade on it. The oil will peel off.