Actually you don't have to evaporate everything.
If your freezer gets below 32 degrees (F) you can do a freeze precipitation.
Simply evap 1/2 or more of your solvent and stick it back in the freezer. Even a very cold deep freezer will have a problem making spice drop from naphtha if it is not concentrated enough.
A fridge can even precipiatate some spice if it is concentrated enough in the solvent.
So again, I say, just evap SOME of your solvent (1/2-3/4ths). If it becomes cloudy then you have evaped more than enough.
This way you don't end up with a ton of impurities in your xtals.