Won't go off real quick?Ice tea !
Could work...vodka - you can get it super cheaper than whiskey....and just stir in some coffee grounds and filter and BABOOM! Whiskey color....
Never seen it I'm afraid!I refer you to the movie Mr. Roberts.
Mr. Roberts (Henry Fonda), Ensign Pulver (Jack Lemmon) and the Doc (William Powell) make a bottle of fake Johnny Walker Black.
watered down coke
as far as going bad, what exactly are you wanting to do? ie drink it a month later or ?