... will help remove the crystal better than plain water.

Then for TOOTHED zippers rub on simple candle wax or a BAR soap.
For 'spiral' toothed zippers, just rub on BAR soap.

You have to be REAL CAREFUL with (some) zippers when using 'dry' sprays as many times the 'carrier' of the spray can 'soften' (swell) the surface of the 'teeth' or 'spirals'. ..... depends on the Mfgr. of the zipper: RiRi zippers seem immune, YKK seems to swell.