The point is to cleverly stuff them, and then give them to the waiting DoberMaw, to be tossed about and nosed around and licked until all the treats come out and it just smells vaguely of peanut butter and deli products. Freezing said items definitely increases the longevity of this venture, which is timed to both distract the Elka from me, that I might accomplish non-dog things about the house, and to mentally wear her out, so she might nap and let me accomplish non-dog things about the house. Many trainers, some of whom I like and some I don't, say "a tired dog is a good dog", and that is a fact.
The Monster Mouth came into our lives towards the end of last summer. Like the clicker, I bought it at Tractor Supply on a lark. I thought it looked fun, and perhaps challenging, and the rubber didn't smell bad. These things are important.
Originally, the Monster Mouth had something of a netting-material ponytail, but Elka set her molars on that, and I got rid of it. Other than that, the wear is minimal; the picture above is recent. The rubber has suffered only a few dings from its frequent usage. The divider in the middle is a pretty fantastic feature, as it works with the teeth to prevent the free-fall of the inserted treats.
With a bit of hand strength, you can hold the Monster Mouth flexed open in order to better stuff it. Typically, my first layer will be something loose but soft, like some shredded cheese. On top of that, I'll tuck in a couple of slices of deli turkey, or pepperoni, followed by a handful of Elka's kibble and some carrots, crunchy stuff like that. I then use a generous knife-full of peanut butter (no double dipping! Unless you have a dog-specific jar, of course) to shellac all of it in there, and wipe the knife off on the teeth. More often than not, I did not think to do this ahead, and so I hand it to the waiting (and eagerly whistling) Elka. I say "take it", and she does. I then say "on the floor or on your bed", because peanut butter couches are not my idea of a good time. Frequently, she will stick with this single admonishment and not need reminding.
(Note Gumby in the foreground? Here's here to help)
Non-frozen, it typically takes Elka around ten minutes (and that is a generous estimate) to divest the Monster Mouth of its bounty and lick away every last vestige of peanut butter.
All in all, it was a good, sturdy, interesting-for-the-dog impulse buy. It hasn't dethroned Gumby, even though Gumby does not dispense treats. Plus, I get the bonus of turning to Elka and saying "Elka, where's your Monster? Can you bring it to me?" And she does.