Yeah, that's a tough one... indeed, as OTD has pointed out, a search of the forum will certainly return many threads where this issue has been discussed... even outright argued about. I believe it was PlumDragon who uses the rice wine freeze technique with good results. Seems like a lot of hassle to me, though. Although that's how you'd have to do it if no cheap vodka was available.

You may have different taxes for pure lab-grade ethanol. Try calling some chemistry supply houses to see what they can offer you. Though you might have to buy a 55 gallon drum of it

Outside of distilling your own or using isopropyl alcohol (not recommended) you can always try using vinegar. Do a thread search for that one, too... much debated but worth a try. The properties of the formula will likely be modified as a result of vinegar base, therefore I suggest you modify the ingredients to reflect the warm, astringent nature of the vinegar (also depends on which type you use). Avoid white vinegar straight, I'd say... the acidity is just plain too high.

good luck

herb ox