Good argument Marc. I have exactly the same experience when i dose voka for a span of 2 months, and gotten the same ill effects of unsightly green cyano, sps stn and out break of ich.
I am pretty sure of the above comes upon only cause by vodka, as i have not done anything else extra during the 2 months of vodka dosing.
After i decided to stop Vodka, it took me another 2 months to restor back to previous healthy condition.
Just like what Marc says, the vodka serve as a fuel for both good and bad bacteria. So i kind of come to a conclusion that rather than to boost the good bacteria using Vodka which results in growing of bad bacteria as well, why not just stick to a regular regime of dosing good bacteria via proven bac products.
IMO, to reduce PO4 and NO3, using Vodka as the only solution will results in more problems, especially for sps.