I don't see why... just leave it out long enough and the water will evaporate too. I know people use everclear and thats 95% ethanol, so I doubt a 4% difference makes that much difference. when all of the visible liquid is done you could just spread out the herb material on a plate or baking dish and it will dry pretty quickly. theres only a few ml of water in it anyway. oh well, either way I did it already, so we'll see what happens. about .9g of some old deems I had lying around in the freezer and .9g of spearmint leaf. used 40ml of the 91% IPA.