it indeed may have had a leather grip between the bulbous bits and even a velvet covered shaft.
i don't think having a more secure grip would make it any more practical, in fact i'd bet having it slip out of your hand after getting stuck in the target would be an advantage rather than pulling you along with it because you didn't lose your grip soon enough.
even if you used it and didn't lose it (or your own life) it would be rather difficult to clean.
most islamic & indopersian maces were basically ovoids or cylinders without flanges or spikes to get caught in clothing or armour (or flesh). the most extreme maybe the head shaped ones, or the flat sided hex/octa-gonal types.
even european spiked and flanged maces the pointy bits were normally anything but acute so they would be unlikely to get stuck. the more extreme decorative ones being just that, decorative.