No wash required, its all about trnsfering your solvent a few times before you get to the evap dish, tea contamination drops stick to the container, and less gets transfered each time.
As for freezing, best is to let it cool down as slow as possible, I believe optimum temp to be around -20C, I just stuck it in the freezer before bed time, My friend and I were shakeing bottles during our bbq, so nothing serious was involved. Every time you do it it will come out a little better, thats the whole point to lots of practice. Hell I didn't even weigh out ingredients, I just guesstimate, always on the watery side rather than the barky side, My stuff seperates in like 5 minutes flat, and with none of the hassles of people who try to put too much bark in a bottle and go nuts fighting emulsions.
Another immportant thing is to experiment with diffirent brands of naphta, the only brand I've tried that gives snow white crystals is Neon. (also the cheapest brand I tried)
The taters serve as a reminder how hard it is to actualy make any amount of food and how long it takes. I bet its gonna taste good though, knowing I planted the one that started them all of. The photo doesn't do the large one justice. I was realy proud pulling that one out.