There is a parasite kit for kids that you can get at health food stores (online if not) called ParaGone for kids. It comes in a two part kit, capsules and tincture. There is also Clarkia which is a tincture of 3 herbs (green walnut hulls, cloves and Wormwood ), which may be easier to administer to a small child. The dose for Clarkia is one drop per 10 pounds of body weight, once or twice a day. Google for Clarkia or use the link at bottom of page.
My daughter suddenly developed hypoglycemia in 2nd grade. It turned out to be parasites. She went on the Paragone for Kids and has been fine ever since. I cannot remember if it was one kit or two that she went thru. For your grandson, it may take a month or more before you see an improvement in glucose readings.
The Paragone for Kids has more herbs that may work a little more thoroughly. You might want to try to get the capsules in him too. Humaworm (Ask Humaworm on Curezone) sells a dewormer for children. That also contains more herbs than the basic 3 dewormer herbs (green walnut hulls, clove and wormwoood). You might want to call them and see what Dr. Bailey recommends.