Until you’re able to get the mister sorted out you could set up a dripper. It can be as simple as a bottle with a small hole in it. Also, are your feeders hydrated? That can help. For my roaches, and crickets when I have them, I use a bottle cap with some cotton in it soaked with water. I’ve actually watched the roaches all huddle around to drink after shopping, kinda cute! You could give him a couple horn worms to get some more moisture into him as well. Not a staple to be fed every day, but they are full of water.
Given that you said his urates are white, though, it may be wise to review your lighting and supplementation. White is an indication of good hydration, and eye issues can often be indicative of a vitamin issue, especially vitamin A.