I wholeheartedly agree w/ John on the coffee grinder - you can even get a new "cheapie" for under 10 bucks which is all you need. The powder will dissolve in a few hours vs. a day or two unground. Mix ur own is DEFINATELY the way to go ...
I too use a mason jar, but I use a sharpie on blue tape and stick that on the jar; date/time mixed, color (or mix) and # cut. No need for acetone!