You should teach your son a "conditioned reinforcer". This is a word that takes the place of a clicker. The special word lets the dog know that he has completed the task correctly and it signals that food is coming.
The benefit of having a word is that the dog knows immediately if it is right, you have it wherever you go (unlike a clicker) and it serves as it's own "reward" so that eventually you can move away from food.
Some people have uncommon sounds like clicks or words like BING. I think this is too hard to remember and the neighbors tend to stare. I simply say GOOD.
Thanks for the great comments. Logan is working very hard and so is Poppy. As you might can tell Logan really wants her to learn "play dead" but we have not worked on it, she was just still chewing her treat in the video.
cbrand- I will get to work on the conditioned reinforcer. I generally tell her "good girl" after a command, so good will work for us to, I'll start Logan using it also. We currently use OK as her release word from a stay command. Should we continue to use OK or should the release be the some work as the conditioned reinforcer?