No, I haven't tried it yet, but that's mostly due to my procrastinating nature.
Curiously enough, I think ingesting isn't that bad compared to application.
I'm like a little kid when it comes to pain from eczema. E.g. I take ages to start my showers because it always hurts so much when the water initially comes into contact with the wounds. Bah, I'm starting to ramble.
Anyway, you said before that old urine will sting, and fresh urine won't. My past experience with that burst blister did come into contact with fresh urine, and it did burn. (Incidentally, I didn't know I had a burst blister until the urine came into contact with it.)