So far I'm not impressed. It has loosened some of the crud on the inside of the keg, but it's still there. We'll see tonight but I'm not terribly optimistic.
The small amount that ran down the side of the keg did do a solid job of removing some leftover label adhesive. So I'll probably still keep it on hand for any de-labeling, at least.
In fairness, this is my first used keg I've had to clean, so I've never used oxy in this sort of application in the past. But Oxy has never let me down before.
We'll see how it looks tonight.