Go Jacks, we are pulling for you.
I've heard that Apple Sauce can lower appetite and cause runs (but works great for impaction!) so avoid apple. I also don't think sweet potato is a good one, going by the Beautiful Dragons site. But chicken with veggies will give moisture and protein so it seems to me like a good one and as mentioned squash and carrot, etc. If Jacks is completely avoiding veggies perhaps a mango baby food or diluted with water? Normally you don't want to give them a lot of sugar though so maybe someone else will have some better advice.