Spry mints have an uneven shiny surface that can get stuck in the mouth of the original model.  It's also small enough to dispense two at a time.  I've included two models.  One with a slightly wider mouth to the original (pictured in red) which will dispense two mints at a time without getting stuck.  The second model also has the wider mouth, but a modified loading chamber to allow one Spry mint to dispense at a time (pictured in black).

I included .STL and .3MF files if changes needed to be made.  

These were printed in PETG with no supports. .20mm Structural, 0.4 nozzle, 15% infill.