One of my favorites is carrot and pineapple, I know that doesn't sound very good but it's really yummy! Uny's 'apple salad' sounds pretty darn good too, I'll have to try that one.
I think it's very wise of you to try and get your son acclimated to the idea of the IP before you start with it. The fact that you got him to do the first hot/cold shower is absolutely AMAZING!
I just know you're going to have a wonderful testimony for us to read as your son heals!!