Fras and shed skins don't really have a small, as long as they are dry. You should be able to have well over an inch of fras before you clean out a colony with no odor issue. They do need some amount of air flow, or they will smell musty, but it shouldn't be overly noticeable. I have all three of my roach bins open, but in a closet, and there is almost no odor when I open the door.
If there are no dead ones (check under your egg crates for dead too - because they are such large insects, even one will send off a really noticeable smell when it decomposes), and humidity isn't too high, try changing out the egg crates. Mine get stinky way before I need to clean out the tub!
You can also try putting a pan of baking soda near wherever you keep your roaches to neutralize any smell. I use a bread loaf pan with half a box of baking soda in it, and sometimes I'll even add in a few drops of lavender essential oil. I don't add the oil for the roaches, but just because I like it. That way my entire closet is an air freshener and makes the room smell nice. XD