Vodka increases bacteria which will help reduce nutrients. However it also increases bad bacteria which could harm your tank if you dont see the signs to reduce it.
I would leave it for more advanced hobbyist.
You could try Bio digest and biotum, both are bacteria based and will not cause any problems.
So far most people have be impressed with the results.
Here is more info
http://www.fnzas.org.nz/fishroom/-vp131201.html