I also have a small quantity of crickets, so I understand your problem.
Here's my experience. My domestic crickets live in 30L plastic box. I cut out half of the lid and glued a mosquito net on it. This is a better ventilation than just holes. On sides of the box I made 0.7-1cm diameter holes for better air flow - approximately 12-18 holes on each side, and covered them with a net too. I read and actually see it myself, that when crickets like it inside, they don't try to escape, so I never saw a cricket near the holes, but still for better safety I covered all holes with a net.
I built a small town for them inside. I also tried to switch them to egg cells, but they didn't like it, me neither. Looks like they are creative folk, like the thing aesthetic . )))))
I don't use substract for crickets, substract is hard to clean and can cause problems. I use simple white paper towels, and they seems to like it. Besides, it is really easy to clean. I clean once a week just for prophylactics, as the box itself completely clean. If I would use substract, I had to clean more often, and this way there is no smell and dirt.
Here's the photo - the crickets ran away from the camera and from the loud noise, but they are all inside ))))))))) They love the coconut house, the carton tubes and the rock. They have a day schedule, during the day they hide inside shelters except females, who lay eggs. In the evening they come out and activities start. I adjust to their schedule, so I change the food and clean the box when they hide during the sleep hours.
It was different with egg cells - as soon as you touch the carton they started panicking, hop around. While with this setup, if I happen to touch a shelter, they just move to another and sit there quietly.
All this will work for a small quantity of crickets, enough for 1-2 geckos.
The most concerning part was the cleaning, but I have zero runners until now. Looks like they like their shelters so much, that I can move the shelters with crickets inside to another box while cleaning. Some hop outside on my hands, but immediately run back into the shelter. I never lost a cricket during cleaning. I have no idea how to clean containers with narrow opening, so I passed on ExoTerra and other companies cricket breeding boxes. My box is a simple organizer box with wide opening, so it's easy to clean. I think easy access is important for easiness of cleaning.
The height of the box is 32 cm, it's not too high for domestic cricket, but they don't hop out.
About the water sponge. I have 33 C at home, everything dries almost immediately. I can do a laundry and 20 mins after take it off completely dry. ))))) Water in shallow drinking bowls evaporate within 2 hours max. A carrot becomes a stone within 3 hours, so I make small portions and change them few times during the day. I put the water sponge into the drinking bowl, soaked with water and without squeezing. The water drips into the bowl, and remains soaked, while crickets drink from the top. The sponge does not dry for about 18 hours despite our heat and dryness - we have only 35% humidity in home. It also depends on the sponge material - the larger the bubbles, the faster the sponge will dry. This sponge can be soaked twice a day in the summer, and I recon once in two days during winter.