Sorry, I wasn't clear!
No, I just meant tilt the bottom box up and off the bottom board enough have room to sweep the maggoty things out. You need to do this daily, so unpacking your hives from the topside probably is too much disturbance, too often. But you can access the narrow space under the bottom box by lifting it a bit w/o disassembling the stack. This won't work if you've already got multiple boxes, but since this is newly-hived colonie I figured you might not have a lot of heavy stuff in the stack. That's also why I added the other way of laying something on the bottom board which makes the larvae to go hide under, and then allows you to get them out when you take the board out as they will be clinging to the underside of it. But, as I mentioned don't add a bee-proof hiding place unless you know you can remove it every day, otherwise you will only be adding to your problems. It would be like putting in a green drone-cell frame and the never removing it!
Enj.