Help! Mouthwash fell into aquarium!!?

What I can recomend you do is a water change. Maybe 50%-75%. In case you don't know just use a bucket or if they have a gravel vacume to take out 50% of the water. There is no garenty the fish will survive. And don't evan think of putting febreze or any air freshener to make things smell better, that will make the situation even worse.