I personally wouldn't use anything with food in it (like real corn starch, sta-flo, which I think has corn starch, etc). Too much temptation for bugs. Maybe if I was washing it shortly after but then if that was the case I wouldn't be starching or pressing it.
As for the vodka, if it's clear I doubt there's any starch left in it. From what I have read it starts out with starch but in the process of fermenting, the starch is converted to sugars.