A humid hide would solve all problems. The other thing to remember is inside the hide is a microclimate and ideally the humidity is measured inside it. The way cheaper digital hygrometers work is very very inaccurate and sensitive to contanimanates (dust dirt) they are often wrong more often than right. The test is easy and cheap it is called a salt test and will confirm the accuracy (or inaccuracy) easily.
http://www.cigarswag.com/index.php?r...formation_id=8
The cheap analogue type that have a calibration screw seem to be very good and can be made accurate if needed. You can figure out the difference and just add or subtract but it will change depending of substrate, snakes actions and the salinity of the humidity in your area.
Bi-metal springs are not as sensitive to dirt and salinity, the snake can still knock them about however.