I don't think that guy was able to get the coconut oil while at the recovery center. I think giving a more helpful context for viewing his history of addiction was much more helpful than the recommendation for coconut oil.
Another heavy drinker I know does fine while on "vacation", but "stress" in his every day life leads to excess drinking. I have no influence with this one, but I'd try to get him to eat more sweets when in stressful situations - juices/etc. I've heard an old treatment for alcohol withdrawal is to feed them lots of sugar. Here's a random NY Times article that says sugar helps reduce cortisol levels: https://well.blogs.nytimes.com/2015/04/23/sugar-as-a-stress-...
IMHO, sugar in juices and other foods is basically fine; starch is 100% glucose and is a greater contributor to excess weight. Lots of caveats with regards to the sugar issue...