What I've experienced myself (and seen other people say too) is that the water needs to be actually boiling. I've only done two ponies with monofiber and had success getting it to lie flat by pouring boiling water on it, but just hot didn't work. I did still have a couple of strands that wouldn't lie down that I had to clip off, but it was literally one or two hairs. I haven't done curls, but I've seen someone here who has, wish I could remember who. . .