I use the same setup as Tom with great success. The eggs are surrounded by air that has a relative humidity of almost 100% without sitting in a wet substrate. The only thing that I would add is don’t panic when the eggs start to dent in after 4 or 5 weeks and add more water. Most of my eggs dent in the last 2 or 3 weeks of incubation. Good luck next year and don’t give up!