So I have a roach box with soil and places to hide and breed, but can I swap out the soil for sand so I can find them better? I’m just concerned if the sand gets stuck to them and my Cham eats it, if it will affect her. Thanks!
Most people use something sift-able. While kinda gross, optimal is an inch or 1 of frass, but that can take a while to build up. But really, why are you not using egg cartons for hides? The soil or whatever is to maintain humidity and for a place for the babies to hide and feed, and for the cleaner crew to process "stuff". But most that are good eaten size should be hanging out on the egg crates.
Egg crates are probably the best option here. You don't have to use a substrate to maintain humidity, which sounds like it isn't optimal for you anyway if you're having trouble finding the roaches. If you're breeding them and need to think about humidity a ceramic heat emitter, and some water crystals should work fine.
Sand is not recommended because it can be abrasive to the roaches. It is also hard to create a humidity gradient with sand, if you're going for that. As mentioned before, use coco fiber for substrate and cork barks or egg crates for hiding. Or go with no substrate and use egg crates. Most of the time only nymphs burrow and adults/sub-adults hang around the egg crates/cork bark, so you should be able to find those more easily.