That's funny! Why are boys so gross anyway, hmmm...mine was the same at that age. Don't forget you could send him out with a torch and salt too since he's not fazed by unpleasant things and get him to do the dirty work.
No one in my house drinks either, which is why I know the lemonade works. Any kind of soda will do, just whatever you have to hand. I find a jelly jar's about the right size to bury.