I'm 39, but when I was 2, my mother said I had roundworms. Since then I have had several health problems, Type 1 diabetes included, but also the SAME foot pain you are describing, even 8 hours of sleep doesn't help. I tried the Epsom Salt the other night also and it helped.
How about showing him some pictures of worms. If that doesn't get his attention, then try to sneak the cleanse. I'm sure he has heard of people getting pinworms. Well, their not the only ones you can get. My husband hunts, and he killed a deer one time that was dieased up with worms. I'm sure he probably got the worm eggs on his hands when cleaning the deer and now has the worms himself.
Dr. Hulda Clark says you can rid yourself of about 100 types in 5 days. If he would be willing to give that a try, I'll type you up the stuff out of her book.