Ever since my boys were young, long before D, I never let them eat the candy right away. Yes, when they were really young, we only went to houses of people we knew but I wanted to start out with the same rules we would have once they got older and went to more houses. No one eats anything until we can get home and I can check over the candy. I toss out anything that seems 'tampered' with. We also limit how much they can eat that evening and ration it out over a couple of weeks (and finally throw out a bunch of it.) Since this started long before D, it was easy to continue after D dx (which was just a couple weeks before Halloween one year.) Oh, and I also often give out toys. And have recently started giving out small bottles of water too....they love it!