Have the first camper start out with water in his/her cup. Camper 1:Time for mouthwash! and puts the water from the cup they are holding into their mouth
Camper 2: Where's the last of the mouthwash? Notices that Scout 1 is using it.
Camper 2: Can I use that after you?
Camper 1: Pretends to spit the water through camper 2's ear. Camper 1 makes their mouth look like it has no water in it anymore and Camper 2 makes it look like they have water in their mouth. This continues through the line until you get to the last person in line. They will have already put water in their mouth and will spit it into their cup and exclaim loudly man (Camper 1's name)what did you have for dinner???!!!