Concentrate did not help. I didn't have nopedostalkers so I put it in, and that doesn't seem to do anything either. College townies, trying to cool down after working out on the treadmill, were still able to cancel her job and start water balloon fights with her.
As an experiment, I lined up my Sim's queue with eight "Work as Barista". The first time, she went through all of them (immediately canceling out one to get to the next one) and got a lot of money. The second time, the off-duty barista interrupted to bug her and managed to cancel out every last one all at once.