I've been vodka dosing for not quite 2 weeks. In my case its been hair algae that finally pushed me to do this. Last year was a year of upgrades, new skimmer, lights, cleanup crew, better tank maintenance, GFO/Carbon reactor, new powerheads, cleaning shallow sandbed in main, but not touching the DSB in the 55 filtration tank. I even have a new 30 gallon sump I'm working on, just need new pump and some more baffles.
So far the vodka dosing is pulling out darker skimmate, clearing up the water, and the hair algae is finally starting to lose its hold. In other words its not as green and seems easier to manually pull the small amount that is left. Film algae is also becoming less heavy and easier for the cleanup crew to manage. Light penetration in the clearer water is causing the corallline to explode and in lower areas of the tank become quite a beautiful dark pruple.
For me it was a last resort after a year long battle scrubbing and removing hair algae. So far I think it will be worth it.