A litter-shovel will help you to get all the litter into the helper and instead of shaking the helper you can just slowly go through the pellets with said litter-box-shovel while you have the helper positioned so that everything that falls through the grid, ends up in the litter-box below. Once you have gone through it, you can just put the helper including content onto the rim of the other litter box while you discard everything out of the litter-box you are currently working on and also clean the box itself. The cleaned out pellets are then put into the clean litter-box and new pellets get also added to the clean but scent-soaked "old" litter to have the proper amount of litter for your kitties. This is what you do to clean out all the litter boxes. (Encasing the wood with silicone glue and also covering the grid where it is stapled to the wood works best is when you use single-use gloves to "smear it" all over the place. But make sure to let it try on for example tin-foil so your floors stay clean. But the surface that comes into contact with the foil should be either already tried or not covered in silicone-glue. Which means you need to leave it out for a day or two to try it and then work on it again.)