My wife bought fruit drinks and poured wine into the bottles which really effectively masked the smell. Her favorite was orange Gatorade, but anything with a bottle and colored liquid worked. Slurpies worked nicely in the summer for her too.
In a pinch she just used Nalgene bottles and said it was water.
She, however, isn't dumb. She's an alcoholic who does and says incredible dumb things when she's drunk or drinking.
Now that she's in a lengthy period of sobriety we laugh together about how she used to think she was getting away with it when my daughter and I knew the whole time.
Cyranoak