Honestly I wouldn't feed my frog anything that has been made food for another animal, bit if it isn't harming him I guess it's ok for a short term period. I would still feed him crickets though, as Don said, they will fill his belly and provide ruff-age whereas the Cricket Quencher is a supplement that is basically just water with vitamins. It's ok if the frog doesn't seem interested in crickets when you first bring them home, all frogs go through an adjustment period where they are scared and not quite sure if you're a predator or a friend, so they will sometimes shut down and not eat, or sleep for days. It's totally normal for the first few weeks.

Is the reason you're not feeding him crickets because of his leg injury? There are remedies to that situation.