These are some simple desiccant holders that fit inside the spool cavity. I couldn't find exactly what I was looking for, so I made something myself. Here are the features I focused on:
*A partial fill allows the cup to act as a tumbler and mix the beads, so they all have an opportunity to absorb moisture roughly equally. With a full fill, the center beads may not provide much drying.
Instructions for use:
If tightened down properly, the container should grip the spool, allowing it to rotate with the spool and tumble the desiccant beads as it rotates in the AMS. The container is intended to live with the spool, so the spools can be loaded into the AMS or stored without removing the desiccant.