Smart kitty. I have always read how some kitties open cupboard/containers just to steal treats, now I see it, lol.. ET's treats/kibbles are in a bottle inside a larger non-tight bin, placed at a corner inside his room. He just needed a push, all the bottles of treats/kibbles will topple over, but he never did it, not once. Whenever I open the bin, he will wait anxiously for his treats, that's about all.
He knew "Sit" right from the start, I managed "Go back room room", "Go", "wait wait" without treats, it is just something he kept hearing me say and he knew what I wanted. I have just recently started "come", "up" with treats. He knew "comb comb" too, whenever he hear this, its time for a brush and treat and he readily come. All of these are done without the clicker.