Yes, ID, you hit the nail when you talked about eating on a "regular basis". Water Fasting is fine, but it's what one goes back to that really counts. I think the Raw Vegans have the best idea if Greens are included along with the Fruit.
That Pineapple sounds yummy, but may be too acid as you mentioned.
I've decided to drink water only when thirsty as several of you mentioned. If the 'Masters' suggest doing it that way, it must be right. However, I heard, or read, that Ghandi added Lemon (or Lime) juice to his water during his fasts. I considered that, but won't do it.