'Where is it' or 'Find it', said quietly is what I use when out hunting. Petie responses the most to those words, but then I have hunted with him the most. The words are said quietly because you shouldn't have to 'pump' the dog up, nor do we want them over excited (that can get their faces ripped off as the dog enters the earth without thinking or too fast etc.) Those words will have him casting about, standing on his hind legs air scenting etc.
Those words flip his brain to 'hunt mode', I am careful not to use them when competing in agility etc, although I doubt he would respond if anyone else used them around him.
If you say 'Laura' (a friend that Bobbi adores), will send him running to the livingroom and looking behind the sofa. Go figure, she has never hide there on him, we don't know why he does that, but its funny.