I keg beergaritas for my wife and her friends when we have parties. It's got lemon lime soda, beer, limeade and tequila in it (it's actually kind of refreshing). I've had to change the seals on the keg to get the lime odor out of it. Now I dedicate a keg to her beverage and just clean it out afterwards like a normal beer keg, but it's only used for that.
"A witty saying proves nothing." - Voltaire