Ringrey,
if ya get 2-3 sample jars with 27ml meth in then add 0.5ml wvo to one, 0.25ml to another and 0.1ml to a third you can then compare them to future 3/27's and get an idea of the amount of fallout, personally I will accept up to 1ml if time predicts, but prefer to get to, or as close to, no fallout if time permits.