My girls get excited about getting misted with a spray bottle of water. If I am trying to clean sometimes, I give them a rag with a squirt bottle with water and let them "wash" the windows. I decided to use this to motivate them to speak in Spanish.
I asked each one a question about where something was in the room, what someone was doing or what color was something. If they answered it back in a complete sentence, they got to squirt water on whoever they wanted and they said, "Agua Va!" They could ask me questions, too and I squirted them. I know from experience it's good to make sure they know only one squirt is allowed and they have to have some distance from you :) There was actually a little breakthrough with my 2 year old. She was speaking more in sentences and then when we were about to read a book for bedtime, she said, "Read it in panish." Even though she said this in English, I know she is starting to get more excited about Spanish!
Let me know if your kids or students think squirting is as much fun!