I take the insect with the tongs and rub it on the frogs mouth. you may have to practice with this method for a few minutes but if the frog nudges the tongs or backs away than I would try tomorrow. my frog stomps his feet when he is not hungry and gets upset.
I never let insects run unsupervised in the tank. roaches are ok but crickets are annoying. they chewed a hole through my styrofoam background so I have to go back to tong feeding. plus some insects will bite your animal, thus causing sores and stress.
gut loaded dubias, crickets, and earthworms are the best variety in my opinion.
I feed every other day and dust once a week, but I must tell you that I have an adult. some dust everyday, but I think thats overkill.