What nozzle size should I use for filament containing glitter?
Fact is that you encounter clogs with this filament, so trying a larger diameter nozzle is an option to solve this. Nozzles are very cheaply found in various sizes, so buy a few and experiment. Commonly found larger nozzle sizes are 0.5, 0.6 and 0.8 mm nozzles, even larger nozzles exist, like e.g. 1.0 mm or even larger, but keep in mind that the hot end needs to keep up heating of the extruded filament, so deposition speed may need to be reduced for larger nozzle diameters.

Alternatively, you could fight clogs the usual way by playing with temperature, layer height, retract settings, oiling filament, purging nozzle from previous filament or cooked up residue, etc, etc.

Quoting someone's experience:


  As far as differences, here has been my experience:
  
  
  0.5 mm low back pressure (High speed), and very hard to clog,
  0.4 mm medium back pressure, rarely clogs,
  0.35 mm high back pressure and very easy to clog.
  




Edit: According to Proto-pasta, concerning filament with glitter, a 0.4 mm nozzle should not be a problem as the glitter particles are smaller, the print layer thickness definitely can be a problem. However, they state that a larger diameter nozzle will result in more sparkle as the glitter is not laid too flat.