Cypress does well in high-humidity enclosures because it doesn't mold like aspen does, and I love using it in the winter for my boas, rainbow boas, and ball pythons as my house gets very dry. Fortunately over time it does dry out, and as you spot clean and replace small amounts of it, your humidity should stabilize.
If you need to dry some out quickly, spread it onto a large baking pan and put it in the oven at 175*F for a few minutes, then turn the oven off and leave it in there while your oven cools. Repeat as needed until you have enough dry mulch. I also have some that's been airing out in a tub ready to go to replace mulch when I spot clean.