Yes they work, get a dogtra model, haven't bought one for nearly 10 years but don't think the price has altered much, about £65. Forget about those citronella collars, any dog with a hint of drive will ignore the pathetic spray of mist, also people will tell you that the volt is more severe than a spray of citrus, whats more invasive, a quick correction or burning citrus up a dogs olfactory organs, its all perception......