Wrong on the humidity. They don't live in the desert - they live in forests with high heat and humidity. They also live in burrows and termite mounds that are more humid than the ambient air.

I keep mine between 50-60% and up it to 70%+ when they go opaque. But since my house doesn't go below 40% (humidifer) a little misting is all mine need.

I did bring in some new snakes a week ago and a few had stuck shed and eye caps. After a week of misting (once or twice a day), most of the stuck shed and eye caps are gone.