Alright folks, so here's the latest chapter with my sink.
I didn't try the soda because the nut is UNDER the sink. I DID try the liquid wrench and it did loosen things up... HOWEVER, now when I turn the nut, the shank and flange turn too. In other words, the nut is still FUSED to the shank (cylinder... whatever it's called).
I can't figure out a way to stabilize both of them so I can turn the nut.
Any more suggestions before I lose the rest of my hair and call the looney bin to come pick me up?
Thanks! Jey