I never tried super-strong alcohol, not applied to the skin anyway. I could easily believe that 180 proof (90%) would work much better than vodka (80-90 proof = 40-45%). Or you might try 91% isopropyl alcohol (available from the drug store) and let everyone know how it worked. the 'poison ivy oil' might be much less soluble in 40% alcohol, or whatever skin reaction is involved might require the good stuff.
I would also guess that it might work better to kind of "blot" the affected skin like removing a stain, and throw the cotton balls away fairly often, rather than scrubbing up and down and around with just one cotton ball or paper towel. That might spread the urushiol oil around to a wider area.
I did this once and urge everyone NOT to:
I had some poison ivy on a few fingers, not too bad. If I remember correctly, it had already been there for a day or more, and I assume that I must have washed my hands a few times already (but not with concentrated alcohol.
However, then I sharpened some knives, which at that time I did with oil stones, and set the stones in a tray with a little oil between uses. Well, you get a little oil everywhere when you do that.
There must have been some residual "poison ivy oil" on my skin, because working with oil spread that poison ivy rash up and down my lower arms. I assume that the urushiol from the poison ivy dissolved into the motor oil, and then spread everywhere.