You can also make them in larger quantity using the 1:1:2 parts.
For example - this amount makes about 30 pockets:
1/2 cup Milk
1/2 cup Crunchy Peanut Butter
1 cup Flour
In my experience, dogs prefer whole wheat flour to all-purpose, but they'll eat anything with pb.If your dog is allergic to wheat, you can use any kind of other flour you want. I like the chunky pb because then your dog won't be able to easily detect the pill forms hiding in the pocket. If your dog is allergic to dairy, you can probably use water.
Very simple ingredients that you'll already have at home. Stores beautifully. No mess.