A long time ago in a contents company far far away… Actually, not that long ago but at a time before there was proper use of inventory software, contents would go from the pack out and not reappear at the pack back. Or they might sometimes make it to the pack back without having been properly cleaned. When I started in contents our field services crew would complain that production was a black hole. Things would go in and sometimes not come out. Regardless of the size of the items or job, there were issues with making the pack back whole. Fortunately, not long after I arrived I was delegated the task of implementing a new inventory software. This helped a lot.
Inventory software is not just great for finishing a pack out with speed and precision, it can also be very helpful in sorting out the warehouse side of the business. Vaults can be assigned as locations and boxes and items can be scanned in as such. The movement of contents from the house to storage to cleaning to storage back to the house can and should be tracked one way or another.
If you find that things go missing or not cleaned, consider using inventory software. If you have software and are still experiencing these problems, reexamine your methods make sure have set up proper procedures.