When swim freeze precips a benzine re-x he was having to do it multiple times in order to get white crystals. he noticed that if he started the freeze and let it sit in the freezer for 15-20 minutes, that the oils were the first thing to drop to the bottom of the shotglass were oils/alk's.

Swim now makes it a practice to let freeze precip happen for 15-20 min, then pours off the cloudy benzine/spice into a fresh clean shotglass and then puts the new shotglass back in the freezer. Nice clean crystals emerge that much faster and saves 2-3 re-extractions. Of course the first shotglass is used in this fashion over and over in order to capture any leftovers.

Hope this info helps someone out there....