Yes, it certainly can.
However, it's best to use a small amount and test first before removing rust from a large area. Also, you need to be really careful using it - it's a very dangerous chemical.
Here's an article that'll tell you all you need to know about safety precautions:
And here's a forum of people who use oxalic acid to clean up old beer cans for some good 'before and after' oxalic acid pics:
I do hope this helps, if you want a more specific answer, just ask!