I see isopropyl 91% all th time does that count ;S?The metal would have to be exposed to both moisture and oxygen in order to corrode, so your container of spit wasn't doing much but waterlogging the circuit board. However, I'm still fairly skeptical that there will be any noticeable corrosion in Frankie's experiment after 30 days. If there's anything visible it would probably just be some dried salts left behind by Mr. Says_Relax's breath, which could be wiped away easily (those same salts would surely contribute the oxidization of the metal in the long run however). Maybe i'm wrong, though, and the oxidization will happen faster.
Where are you performing this experiment, Frankie? If you're somewhere dry like Nevada, you're probably wasting your time. Unless the air is relatively humid, the moisture in your breath will evaporate too quickly. And if you're really at the bottom of Suda Trench, you'll have the same problem as NES_Rules and his bucket of spit.
Have you ever seen 100% alcohol for sale before? We use it at my work and we have to order it from a laboratory equipment distributor. The highest I've ever seen for sale in a store is 85%. The remaining percentage is made up of water, though, which is indeed more likely to be left behind and cause oxidization after the alcohol evaporates, so I guess pure grain alcohol would be better in theory. I doubt it's anything much to worry about in reality, though, since you're not using it very often.
...word is bondage...