Earthling,
Filtering alcohol. Yes, that is exactly how you get concentrations over 100 Proof (50%)- by filtering alcohol through a drying agent such as silica jell. About the best you can do by distillation is 60% but that is expensive - which is why they call 50% 100 Proof - it was the practical limit before other drying technologies became available.

Alcohol absorbs water from the air until it reaches between 6% and 9% water. That's why you see alcohol concentrations of from 91% to 94%. You can make truely anhydrous alcohol, but storing it so it does not absorb water from the air is the main challenge.