I had to read this twice to make sure I read it correctly, lol...
No, you cannot "make eggs hatch more quickly" in any way, not with humidity or any other means...Different species of eggs have different humidity requirements, but they still hatch in a certain amount of time, after the baby bird develops fully inside...No way to speed that process up...
You should be breeding baby birds at all if you actually thought you could speed up the hatching process, as well as not knowing what "nesting material" to use, or that you needed to use it to prevent the babies from developing splayed legs. You do need to use a bedding/nesting material or the babies will have physical deformities, but you're unfortunately going to have much more serious issues if the parent birds reject a baby or babies, or start harming them or kick them out of the nest box, as you'll have to remove them and hand-raise them, possibly from a day or two old...And obviously you're not ready to do that...
Please don't breed your birds again until you educate yourself fully on hand-feeding/hand-raising and just breeding in-general...