Of course I'm late to this thread, but two of my dogs now have been obsessed with the hearts of Romaine lettuce (the white stem parts, NOT the leafy green parts -- it works out very well for our salads!). When Rosalind was teething, I'd stick the white pieces in the freezer, and that worked very well. Zoe's favorite treats were baby carrots, but Rosalind won't eat them.
She's the least food-motivated dog I have ever met, with very notable exceptions for the aforementioned lettuce, beef, and peanut butter. She'll play with food, but she rarely finishes her food.
We need to get around to taking pictures with our FoT pouches! Since I've used mine more, the embossing is almost worn off, but the other one is still in good condition.