I created a simple funnel to refill a chalk ball. It is a funnel with enough width to handle the large “chunks” of magnesium, and a lip that allows (at least my) chalk ball to be attached to it while I refill.
I did put some spare paper below for the operation, to take all the loose chalk that fell off and put it inside the chalk bag after I finished.
This is a very quick design I did for a specific use, it's not meant to be very refined :)
The author marked this model as their own original creation.