Just remember, you're dusting them, not coating them to fry. You don't need a lot on the crix as long as the chameleon hunts them down relatively soon after they're put into the enclosure. Also, gutloading is for making the crickets better nutritionally, whereas dusting is for supplementing. It's kind of like asking, "should I avoid junk food or take a multivitamin?", where ideally you'd do both but either is better than nothing.