I think its not cost or labor effective...not enough nutrients available in coconut water (liquid form).
But it's a great idea...maybe good for certain applications, where only high ph water is available, and a grower needs access to better neutral water, via coconut. (i'm not sure of coconut water Ph, but im pretty sure its acid or neutral, not alkaline)
maybe it could be useful for cerrado sp? where someone doesn't have access to good ph water?
Otherwise, just drink the coconuts, and pee on your plants!
I bet that will be more nutritious for your trees.
( I'm not sure about the plant growth hormone! that could be something your on to!!
sorry I just noticed that part of your post!!)