Actually, the Grand Marnier is one of the Grey Goose slushies; it’s made with GG L’Orange plus the Grand Marnier. The lemon flavor is made with GG Citron.
If you ever make it to Food & Wine, the LePassion slushie is another great flavor of this drink. In May, I am looking forward to trying the La Vie En Rose which I believe is pomegranate flavored.
Delicious drinks, but enjoy them cautiously, especially at first, as they can induce quite a brain freeze.