I used to drink a fifth (750ml) daily of whiskey. 3 fifths is beyond comprehension, that's about 60 shots (1.25 oz per) or mixed drinks a day (keep in mind the average alkie's mixed drink, if they mix it themselves, probably contains 2-1/2 to 3 shots). 3 pints a day I could see. I do know a fifth daily damn near killed me.
Also, mouthwash (20-25%), vanilla extract (5%) and other household substances generally contain no where near the amount of alcohol as whiskey or vodka (40% minimum).