Ruined kettle?

I brewed a couple weeks ago, and by the end of the second batch, needless to say, I had a few too many beers. I decided to just soak my kettle (an aluminum 7.5 gal turkey fryer pot) rather than clean it. I soaked it in water and a scoop of oxyclean free and forgot about it for a couple days. I came back to clean it, and noticed the entire inside of the pot is now black. I looked at the container of Oxyclean, and realized after the fact that it said do not soak in metal containers (whoops). Is there anything I can do? Can I still use the pot, or do I need to get a new one?

Try boiling water in it and see if it won't lift the black coating off it.

If Revvy's suggestion doesn't work, rub a small spot with a sponge and Comet. I have polished up tarnished copper on some of my pots this way. Works well and doesn't scratch the surface but removes oxides.

If Comet does work, you will have to decide:
1. Scrub the entire pot by hand
2. Be lazy and use a polishing wheel + Comet in your drill.

I might be tempted to lean on the lazy side

Your aluminum pot is oxidized but not ruined. Fill the pot with a mixture of white vinegar and water (about one up of vinegar per gallon of water). Let it soak until it is nice and shiney again. Go make lots of beer but don't use oxiclean to clean your aluminum pot.

My wife threw some PBW into a large aluminum stockpot to soak after a big batch of chili, having seen the magic that it performed on my stainless keggles. Skipped right past the black oxidization stage and on to the "WWII Western Front After Heavy Shelling" stage. No amount of grinding was going to save that bad boy - looked like the relief map of a lunar mountain range.

So yeah - keep the caustics away from aluminum...

To clean your aluminum kettle, soak it in hot water, use a paper towel to rub off things that are not falling off (be gentle, you want the oxide layer to stay) and rinse it well then let air dry. Any cleaning chemicals you put in there could potentially react with the aluminum and there really is no reason to use em as you are boiling in that pot.

Get rid of debris in the pot and rinse er good.