I can say for sure the boiling water trick works for horn (at least temporarily). I Soaked the scales in the boiling water for 1 minute, pulled them out, put a tapered chopstick inbetween, flexed them, and then into cold running water while flexed!

You definately need to be holding the scales in the desired position when putting them under the cold water. You can't just mold them then harden. And It took me about 4 tries to get it right so... try and try again!