I think A: You can only use the machine 3 times a round. and B: The GP (Gum-perks) won't last more then a round. I believe the machine can be used three times before it moves, because, if you could only use it three times each round, then it would be unfair for the players that wouldn't be able to afford any. As for how long they last; I believe that they could possibly be similar to the tactical grenades. So they probably could last more than round depending on how many times you use it.