I have to really ask how many of you have thought all of this through. Niles and Savs are wild caught, they thrive in the wild on a diet of - insects. For the most part, the parasites/chemicals found on wild grasshoppers in Africa make anything they would find here look tame.
I have always fed my monitors wild caught grasshoppers from a local park and never had issues with them, I also feed wild caught fish and mice.