I had a cork bark hide for my first corn when we first got her - within a remarkably short amount of time she had pooed all over it which was impossible to get out of all the little crevices so it stank and went in the bin lol. That was without the added complications of high humidity! No more cork for me...
I've never used cork either, but I don't believe I'd ever try it for those very reasons above. It would be impossible to clean, would more than likely grow mold quickly in a high humidity environment (something that freaks me out, lol!) and it would stink in a short amount of time. Not worth it, IMO. ;)